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  • 101
    Electronic Resource
    Electronic Resource
    Crystal structure of methyl acrylate (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1509-1515 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Methyl acrylate, CH2CHCOOCH3, has been crystallized, and x-ray data have been collected at -120°C. The crystals are orthorhombic, space group Pnma, with four molecules in the unit cell. The structure has been determined by using symbolic addition procedures, and refined to a final residual R factor of 0.10. The molecule is planar, and the intramolecular bond distances and angles are in good agreement with values obtained for the liquid monomer by electron diffraction techniques. Considerations of crystal geometry indicate that the packing hardly permits dimerization or polymerization of the molecules in regions of crystal perfection.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090810
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  • 102
    Electronic Resource
    Electronic Resource
    Technique of XYZ photographic light scattering as applied to uniaxially drawn polyethylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1531-1536 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090813
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  • 103
    Electronic Resource
    Electronic Resource
    Sorption properties of polypropylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1629-1640 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The sorption properties of atactic polypropylene (APP) and isotactic polypropylene (IPP) were studied by equilibrium sorption of various organic solvents. The variation of the Flory-Huggins interaction parameter χ for the APP-CCl4 system at 25°C was expressed as a function of the volume fraction v2 of polymer by the relation: x = 0.113 exp {1.879 v2}. The average molecular weight Mc of the polymer chains between successive crystallites for IPP subjected to different thermal treatments was calculated to be 250 to 350 by the equation of Flory and Rehner. From the variation of Mc with solvent concentration, we estimated the number fraction of polymer chains actually contributing to elastic deformation. The clustering function for solvent in the polymer calculated by the method of Zimm and Lundberg decreased linearly from a positive value to -1 with increasing solvent concentration. Clustering of solvent molecules was found to occur more easily in APP than in IPP.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090906
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  • 104
    Electronic Resource
    Electronic Resource
    Reaction kinetics in dilute solutions of chain molecules carrying randomly spaced reactive and catalytic chain substituents. II. Dependence of the ring closure probability on the solvent medium and the nature of the chain backbone (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1657-1668 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Ternary copolymers of acrylamide or methacrylamide with small proportions of comonomers carrying reactive p-nitrophenyl ester and catalytic pyridine groups in the side chains were prepared. The kinetics of the ester solvolysis was followed in highly dilute solutions, so that the rate was controlled by interaction of groups carried by the same chain backbone. Data were obtained in water and aqueous methanol and were interpreted by a computer simulation procedure in terms of the dependence of the probability of encounter between two chain substituents on their spacing along the chain backbone. This probability decreased more slowly with increasing separation of the interacting groups when the solvation of the polymer was reduced, but even in solvents approaching θ conditions the results deviated from theoretical predictions for chains without excluded volume. The formation of cyclic conformations is considerably more difficult in methacrylic than in acrylic chains, although the chain flexibility, as characterized by unperturbed chain dimensions, is very similar in the two systems.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090908
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  • 105
    Electronic Resource
    Electronic Resource
    Diffusion of radioactively tagged D-fructose through swollen crosslinked poly(β-hydroxymethyl methacrylate) solutions (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1725-1727 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090914
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  • 106
    Electronic Resource
    Electronic Resource
    Effect of molecular weight on the refractive increment of polyethylene and n-alkanes (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1763-1776 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: As in the case with other polymers previously reported, the values of the refractive index increment dn/dc of polyethylene and the n-alkanes change with molecular weight. Most of the variation may be understood by examination of the role of density in the Lorentz-Lorenz mixing equation for specific refractivity, R12 = p1R1 + P2R2 used to calculate dn/dc. It may also be shown that as the absolute refractive index difference between solute and solvent becomes smaller, dn/dc becomes more sensitive to density change of the solute.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160091003
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  • 107
    Electronic Resource
    Electronic Resource
    Fold surface of polyethylene single crystals as assessed by selective degradation studies. III. Application of the improved techniques to single crystals (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1807-1837 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Previous studies on selective degradation of polyethylene single crystals with fuming nitric acid have been extended, both by using acid of lower concentration which gave better control over the degradation, and by resorting to ozone as an oxidizing agent which among others enabled the degradation temperature to be conveniently lowered. The molecular weight distribution was followed by gel-permeation chromatography in the course of degradation. Complete consistency between these different methods has been established, modifying some of the previous conclusions reached by this method. The principal feature which emerges is that we have a distribution of fold lengths. The largest straight fold stems can stretch across nearly the entire layer defined by the low-angle x-ray period, while there is a continuous distribution of shorter folds terminating deeper down in the crystals. The limiting depth at which the number of terminating folds becomes negligible can be identified and quantitatively assessed. The method of analysis is described, and individual data are discussed in detail. This picture of a fold surface layer containing essentially adjacently reentrant folds of uneven length agrees with quite recent results on other related chain-folded systems (annealed crystals, short chains, bulk structures) obtained in these laboratories and thus appears to be of general validity. The consequences of the model for our picture on polymer crystals in particular on the nature of the “amorphous” component, are discussed.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160091006
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  • 108
    Electronic Resource
    Electronic Resource
    NMR observations of drawn polymers. VIII. Doubly oriented nylon 66Presented in part at the Meeting of the American Physical Society, Dallas, Texas, March 1970 (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1851-1869 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A wide-line NMR study of chain segmental motion in nylon 66 has been made on a rolled sheet having “double orientation.” In this sheet the crystallite c axis, i.e., the molecular chain axis, is oriented preferentially along the roll direction, and the crystallographic (010) plane lies predominantly parallel to the roll plane, or the plane of the sheet. The direction of the applied magnetic field with respect to the sheet is characterized by two angles, the polar angle γ subtended by the roll direction and the magnetic field, and an azimuthal angle φ. NMR spectra were taken at various values of the angles γ and φ and at three temperatures -196°C, 20°C, and 180°C. The second moments of the absorption spectra taken at 180°C were compared with theoretical predictions of second moments based on two models for the high-temperature segmental motion (called the αc process) in crystalline regions of nylon 66. One model consists of rotational oscillation with amplitudes δ of segments around their axies. The second model is denoted 60° flip-flop motion and consists of rotational 60°C jumps of the segments around their axes between two equilibrium sites with the possibility that the segments also oscillate with a general amplitudes δ around each site. The experimental results are consistent with fairly large amplitudes δ, in which case both models approach the limiting case of full segment rotation. For this reason the experiments do not allow a distinction between the two models. From the second moments at -196°C and 20°C the decrease in second moment due to the low temperature segmental motion, the γ process, is obtained. This motion occurs in noncrystalline regions of nylon 66 and is found to cause a decrease in second moment which is strongly dependent on the two angles γ and φ, implying double orientation of the noncrystalline segments. It is suggested that at low temperatures the noncrystalline segments become immobilized in sites dictated by the crystallite orientation through the extensive hydrogen bonding known to exist in nylon 66.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160091008
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  • 109
    Electronic Resource
    Electronic Resource
    Self-oscillation mechanism of necking on extension of polymersPresented in part as a short communication at the International Symposium on Macromolecules, Leiden, 1970. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1919-1933 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A new phenomenon in necking of some polymers, including poly(ethylene terephthalate) (PETP) was detected. It was found that extension of PETP films under certain conditions results in periodic stress oscillations and a periodic change in appearance of the sample. The conditions at which self-oscillations appear have been determined, and the principal regularities of this regime of deformation are described. The following factors are critical for the appearance of self-oscillation: speed of straining and compliance of the sample. The self-oscillation of stress and formation of the periodic transverse bands is attributed to heat dissipation during necking corresponding to local temperature jumps and periodic strong variation of elasticity modulus due to poor heat conductivity of the polymer. Changing the external conditions of heat transfer influences the possibility and development of the effect. The phenomenon is common for various crystallizing polymers, being dependent on physical properties of the polymer and conditions of deformation.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160091101
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  • 110
    Electronic Resource
    Electronic Resource
    Diffusion mechanisms in solid and molten polyethylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1935-1954 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The diffusion coefficient D and solubility coefficient k of small molecules [C3H6, C4H10, (CH3)4C] are determined at very low solute concentrations in annealed linear polyethylene over a wide range of temperature above and below the melting point Tm. For measurements above Tm the specimen was lightly crosslinked by irradiation from a 60Co source. The diffusion data fit equations of the form D = D0 exp {-ΔHD/RT}. An abrupt change in ΔHD occurs at Tm: representative values (for C4H10) are 4.53 and 14.9 kcal/mole above and below Tm. At Tm, D0 also changes abruptly: representative values (for C4H10) are log D0 = -2.65 above Tm and log D0 = +2.70 below Tm. The mechanism of diffusion therefore changes at the melting point. The melt exhibits typical liquidlike characteristics (negative values of activation entropy ΔSD). The ratio ΔSD/ΔHD = 4β (β denoting the isobaric coefficient of volume expansion) holds below but not above Tm. Equations of the form k = k0 exp {-ΔHk/RT} fit the solubility data. The log k versus T-1 plots above and below Tm are parallel but separated by a step at Tm. If crystallization followed by annealing is assumed to leave a weight fraction of polymer αk (the amorphous fraction) in which the solute can absorb and if the specific solubility coefficient of the amorphous fraction is identical to that of the melt, then log αk Equals the magnitude of the step at Tm. Values of αk determined from the observed step are very close to values of amorphous fraction determined by measurement of density. The solubility experiments support the concept of polyethylene as a two-phase solid with the amorphous fraction of specific volume equal to the extrapholated specific volume of the melt. The passage of a solute molecule from one potential well to another, however, occurs by processes in the melt and the amorphous fraction which are entirely different.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160091102
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  • 111
    Electronic Resource
    Electronic Resource
    Axial dispersion of solute zones in gel permeation chromatography (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 245-265 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The two essential aspects of axial dispersion in gel permeation chromatography have been studied: (1) the relationship of axial dispersion to the continuity equations of chromatographic transport, and (2) the relationship to molecular size and the system parameters of an individual column. Theoretical analyses are presented for both of these problems and are applied to an experimental study of axial dispersion by both zonal (small-zone) and frontal (large-zone) experiments with a series of macromolecular species having discrete, precisely known molecular weights. Theoretically predicted non-Gaussian elution profiles were observed for the small-zone experiments, and axial dispersion coefficients for each molecular species were determined as a function of flow rate. Resulting values were found to be in good agreement with the theoretical equation relating axial dispersion to molecular size, flow rate, and two “calibration constants” of the column. These results provide a rational basis for axial dispersion effects in terms of the fundamental processes and system parameters of gel columns. Extension of the analysis to multicomponent systems is discussed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090203
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  • 112
    Electronic Resource
    Electronic Resource
    Light scattering by cellulose. III. Morphology of wood (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 313-329 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Radial, tangential and cross cuts of Eastern spruce are examined by a solid-state light-scattering method which allows study of light scattering due to fluctuations in density and fluctuations in anisotropy. All of the samples investigated show well-defined scattering maxima which are related to their anisotropic texture with limited contributions from random density fluctuations. The radial cuts give rise to scattering similar to that by a grating with orthogonal characteristic spacings. The gratinglike character is due mainly to the pit structure and their periodic spacings, which can be deduced from the “unit-cell” dimensions of the scattering pattern. The scattered intensity is maximum when the fiber direction is at 45° to the polarization direction; when it is either horizontal or vertical, a distinct “spherulitic” scattering is observed from which size and asymmetry of the pits can be deduced.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090207
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  • 113
    Electronic Resource
    Electronic Resource
    Intrinsic viscosity of polyelectrolytes in salt solutions (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 373-375 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dependence of the intrinsic viscosity of polyelectrolytes on the concentration of added salt is given satisfactorily by a formula obtained recently. A new viscosity - molecular weight relation gives satisfactory agreement with experiments.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090212
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  • 114
    Electronic Resource
    Electronic Resource
    Graphical representation of the state of orientation of polymer systemsPresented at the 19th Annual Meeting of the Society of Polymer Science, Japan, Tokyo, May 22, 1970. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 407-420 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The orientation distribution function for noncrystalline structural units in polymer systems cannot be determined completely from any experimental source; only the second and/or fourth moments of the distribution function, i.e., the second and/or fourth orders of the generalized orientation factors Flmj, can be evaluated. It is there-fore necessary to estimate the distribution function from F2mj and F4mj. In this paper, a graphical representation of the state of orientation is first discussed in terms of plots of F40j against F20j for several types of distribution functions for uniaxial orientation. These are three types of extreme concentration of the distribution at particular polar angles θ0 given by θ0 = 0, 0〈θ0〈π/2, and θ0 = π/2; five types of rather realistic distributions having single maxima at θj = 0, θ0, π/2 and double maxima at θj = 0, π/2, and a single minimum at θj = θ0; and four types of more realistic distributions including Kratky's floating rod model in an affine matrix. Second, estimation of the distribution function for uniaxial orientation from F40j and F20j is discussed quantitatively in terms of the mean-square error by three approximation methods: (a) expansion of the distribution function in finite series of spherical harmonics through the fourth order, (b) approximation of the distribution function as a composite of two components, random orientation and a particular orientation distribution given by Na (cos2θj)a, Na being a constant, and (c) approximation of the distribution function by Na (cos2θj)a alone. It is concluded that when the orientation distribution is sharp, estimation by the second method of approximation gives a smaller error than the first.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090302
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  • 115
    Electronic Resource
    Electronic Resource
    Fox-Flory constant K obtained by viscometric measurements for poly(ethyl methacrylate) and poly(methyl methacrylate) systems (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 483-497 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Poly(ethyl methacrylate) and poly(methyl methacrylate) prepared by benzoyl peroxide-catalyzed polymerization were fractionated. The Fox-Flory constant K was determined for these polymers by viscometry in several good and bad solvents. Application of some empirical methods for evaluation of K are also briefly discussed in relation to our results.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090308
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  • 116
    Electronic Resource
    Electronic Resource
    Scattering of light by deformed disordered spherulites (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 517-529 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The change in the light-scattering patterns upon deforming two-dimensional disordered spherulites is shown to arise from four effects occurring upon stretching: (1) the change in shape of the spherulite, (2) the change in average orientation of the optic axes of the scattering volume elements, (3) the change in deviation of the optic axis orientation angle from its average value, and (4) the change in the distance over which this deviation is correlated. The effects of these contributions upon the experimental scattering patterns are analyzed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090310
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  • 117
    Electronic Resource
    Electronic Resource
    Effects of a static electric field upon dielectric properties of poly(vinylidene fluoride) and poly(vinyl fluoride) (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 585-594 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Dielectric measurements on poly(vinylidene fluoride) at higher temperatures result in anomalously large values of ε′ and ε″ at lower frequencies. When a static field is applied, a drastic decrease of ε′ and ε″ occurs. The effects of a static field can be summarized as follows: (1) the field effect upon ε′and ε″ is more significant at lower frequencies; (2) with increasing field strength, the rate of decrease of ε′and ε″ with time becomes greater and the ultimate values are smaller; (3) when the field is removed, ε′and ε″ recover but the ultimate recovery is incomplete; (4) the field effect depends strongly on temperature. Such behavior seems to be attributable to the displacement of ionic impurities and to their electrolysis. These results provided a method to remove the contribution of ionic impurities to ε′and ε″ and to measure the relaxation process due only to dipoles of a polymer. The application of this method revealed the dielectric high temperature absorption which had been masked by the ionic conduction in poly(vinyl fluoride).
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090402
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  • 118
    Electronic Resource
    Electronic Resource
    Dynamic mechanical and dielectric relaxations of polystyrene below the glass temperature (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 669-686 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Dynamic mechanical and dielectric properties of various kinds of polystyrene, including bulk-polymerized, monodisperse, isotactic, and thermally degraded samples, have been measured below the glass temperature to 4°K. Five relaxation processes are found, designated β, γ, γ′, δ, and ε in order of descending temperature. The β peak (350°K at 10 kHz) is attributed to the local oscillation mode of backbone chains and the γ′ peak (180°K at 10 kHz) to rotation of phenyl groups. The δ peak (100°K at 10 kHz) is observed only in dielectric properties of the bulk-polymerized sample and is assigned to weak polar bonds, such as oxygen bonds in the chain. The δ peak (55°K at 10 kHz) which is prominent in dynamic mechanical properties is interpreted in terms of lattice defects due to a syndiotactic diad inserted between isotactic sequences in a chain or vice versa. The ε peak (ca. 25°K at 10 kHz) is first reported in the present work, but the mechanism involved is not yet clear.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090409
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  • 119
    Electronic Resource
    Electronic Resource
    Determination of the pressure coefficient and pressure effects in capillary flow (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 731-745 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: General expressions for determining the pressure coefficient and axial distribution of the viscosity and pressure in capillary flow are derived for Newtonian and shear-thinning fluids. The pressure-dependent viscosity model is obtained from the WLF equation as derived from Doolittle's free volume theory. The model has also been derived from Eyring's hole theory for viscosity. Poiseuille's equation is modified to correct for the pressure effect on viscosity. A Newtonian, low-molecular-weight polystyrene and a shear-thinning, high-molecular-weight polystyrene were tested in an Instron capillary rheometer. The axial velocity distribution was found to be negligibly affected by pressure whereas the viscosity was shown to increase markedly with a decrease in volume. The resulting pressure effects on the viscosity of both samples were analyzed by using the derived expressions.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090412
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  • 120
    Electronic Resource
    Electronic Resource
    Investigation of cooperative kinetics on reactions of functional groups on polymer chains (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 769-777 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The kinetics of aminolysis of 1,2;3,4-meso-erythritol dicarbonate and 1,2;3,4;5,6-mannitol, sorbitol, and dulcitol tricarbonates by n-butylamine in dimethylformamide solution was investigated. The dicarbonate and tricarbonates are considered respectively as models of dyads and triads in the poly(vinylene carbonate) chain. The theoretical kinetic curves for the dimer and the trimers were calculated by solution of kinetic equations and close agreement with experiment was obtained. A version of the Monte-Carlo method was developed to provide a model for the reaction process by a computer calculation including the neighboring group effect in enhancing reactivity. The theoretical curve for a trimer coincides with the experimental one. These results confirm the accelerating influence of the unreacted neighboring groups. For the polymeric chain the experimental and calculated curves deviate for conversions beyond 10%. This indicates an additional polymer effect, which is as yet unexplained.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090501
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    Formation of spherulites in polyamides. V. “odd-odd” polyamides (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 815-827 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The crystallization of a series of “odd-odd” polyamides has been examined for a variety of fusion conditions and crystallization temperatures. Diverse kinds of spherulites and other crystalline structures have been formed in these nylon polymers by direct crystallization from the melt and by melt-seeding techniques. The structures formed in this way have been characterized primarily with the aid of optical microscopy. In this series of polymers, characteristic textural features yield a fairly unified pattern of crystallization behavior. Crystalline aggregates are formed near the respective melting points of these polymers. In very thin sections (ca. 0.1μ), plateletlike crystals of high crystallinity exhibit optical and diffraction behavior characteristic of single crystals.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090504
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  • 122
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    Effect of water sorption on the dielectric behavior of calcium chondroitin-4-sulfate (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 917-926 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dielectric properties of calcium chondroitin-4-sulfate were studied as a function of frequency, temperature, and water content. The dielectric constant changes very little with water content below “monolayer” coverage, and after that the dielectric constant follows the shape of the adsorption isotherm. The dielectric behavior is discussed as affected by interfacial polarization and by the increase in the rotational freedom of the polymer side chains.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090511
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  • 123
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    Electron microscopy of drawn polypropylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 895-915 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Extremely thin polypropylene films formed by evaporation of dilute solutions floating on water, thin films deposited on Mylar or on carbon-coated Mylar, and bulk samples were deformed; after etching with aqua regia or chromic acid, the surfaces were studied by electron microscopy of surface replicas. At small draw ratio, microfibrils with lateral dimensions of about 200 Å, originating in micronecks at crack boundaries of the original crystal lamellae, were obtained in isolated areas exhibiting maximum local strain separated by large regions of much less deformed material. With increasing draw ratio the necked regions grow, the old structure gradually being reduced to smaller and smaller islands until it disappears completely. The inhomogeneity of strain in adjacent bundles of microfibrils creates a great many longitudinal voids with more or less disoriented microfibrils bridging the gaps. The regular arrangement of crystalline blocks of rather uniform length and width can be occasionally seen on surface replicas of drawn samples, and much better on dark-field electron micrographs of drawn and annealed thin membranes. In the latter case the blocks are very uniform and have similar dimensions along and perpendicular to the axis of the microfibril. The evidence from the electron micrographs, together with previous small-angle x-ray scattering data, supports Peterlin's molecular model for plastic deformation of crystalline polymers.
    Additional Material: 18 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090510
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  • 124
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    Redrawing of oriented polyethylene film (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1083-1096 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Drawn and subsequently annealed polyethylene film was restretched along the original draw axis at various temperatures. The internal deformation was analyzed in terms of the structural parameters of a simplified model. The elementary deformations are the rotation of crystals around the b axis and shear at the crystal interface. The rigidity of the crystal plays an important role during extension; and as a result, disorientation of chains in the crystal occurs at high strain. At the same time, crystals deform in such a way that the crystalline chains tilt about the b axis along the (h00) plane. This deformation of the crystal is affected by temperature. The increase in long spacing with extension can be interpreted roughly by the changes in structural parameters. The strain in amorphous region in also discussed in relation to these parameters.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090606
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  • 125
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    Glass transition temperatures of some linear polymers containing phenyl side groups (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1133-1145 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The glass transition temperatures of a number of poly(vinyl phenyl ketones), poly-(vinyl benzoates), and poly(phenyl acrylates) have been measured by a refractometric method. The effects exerted on Tg by the nature and position of the ring substituents and by the different groups binding the pendant phenyl rings to the polyvinyl chain are discussed. The importance of knowledge of the side-group motions in the glassy state for the interpretation of glass temperature data is emphasized.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090609
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  • 126
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    Viscoelastic properties of linear polymers in the high-elastic state (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1153-1171 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The relation between molecular weight, chain rigidity and the length of the high-elasticity plateau is determined from frequency and temperature dependences of the storage modulus for polybutadienes and polystyrenes with Mw/Mn ≤ 1.1. Use is made of the concept of equivalence of high-elastic states characterized by equal lengths of high-elastic plateaus for linear polymers. The high-elastic states of the linear polymers studied are equivalent if the polymer chains have equal numbers of dynamic segments and if the reference temperature is T0 = 1.22Tg, where Tg is the glass transition temperature. The viscoelastic properties of the polymers in the high-elastic state are determined unambiguously by Tg and the molecular weight of the dynamic segment. The quantitative relation between thermomechanical characteristics obtained by measuring deformation versus temperature under a constant time regime and dependence of storage modulus versus frequency under isothermal conditions is discussed.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090701
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  • 127
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    Crystallite size in highly drawn polyethylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1243-1254 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The size and distortion of crystallites in samples of linear polyethylene were determined before and after plastic deformation. A slowly cooled sample, a quenched sample, and highly drawn films (draw ratio 16) were investigated by different methods. Wide-angle x-ray patterns were analyzed to study the average size of the crystalline mosaic blocks and their distortion. In addition, the longitudinal crystal thickness (in the chain direction) was evaluated by two other approaches, determination of the long period, and the melting temperature of irradiated samples. The results show clearly that the size of the crystalline mosaic blocks changes substantially with drawing of polyethylene. Not only is the lateral crystal thickness affected, but the longitudinal crystal dimensions also change during the drawing process. By the three independent methods we find that the longitudinal crystal thickness after drawing is independent of the value for the undrawn samples, as was reported earlier by Peterlin. The change in crystallite size after drawing is accompanied by a large decrease in crystal volume to about 10% of the value for the undrawn sample. The degree of distortion in the crystals seems not to be affected by the deformation process. These experimental data can be considered evidence for high chain mobility and for the possibility of rearrangement of chain molecules during the process of plastic deformation.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090706
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  • 128
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    Halogenation of polyethylene. I. Bromination of single crystals (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1305-1324 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It has been demonstrated that the fold surfaces of polymers can be specific towards chemical attack, if the reaction is mild and nondestructive of the fold. Bromination of suspensions of single crystals of polyethylene in carbon tetrachloride has been shown to be such a system. This chemical modification of a fold surface is a powerful means of extending the applications of the physical methods available. Several methods were used, among them DTA, DSC, infrared spectroscopy and small-angle x-ray diffraction. Experimental results from these methods lead to the following conclusions. (a) Bromination takes place preferentially at the folds and is consistent with a regular adjacent reentry fold model. (b) Annealing of these brominated crystals demonstrates the major role played by the crystal surface in this process. (c) The preparation and properties of a novel copolymer system has been demonstrated. It is felt that this copolymer system may prove a useful addition to those systems presently available.
    Additional Material: 13 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090710
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    Secondary relaxation effects in poly(1,4-cyclohexylene ether) and poly(cyclohexylethylene oxide)Paper presented at the IUPAC International Symposium on Macromolecules, Leiden, The Netherlands, 1970. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1341-1343 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090713
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  • 130
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    Sedimentation equilibrium in nonideal heterogeneous systems. I. Fundamental equations for heterogeneous solute systems and some preliminary results (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1379-1397 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The sedimentation-equilibrium method is extended to treat nonideal solutions of heterogeneous macromolecules. The solute is assumed to be heterogeneous not only in molecular weight but also in other quantities such as partial specific volume, second virial coefficient and specific refractive increment. General expressions for various observable molecular weights, especially for weight-average, z-average, and number-average molecular weights, are derived. Their dependences on sedimentation parameter and solute concentration are discussed in detail. For the extrapolation of observable molecular weights, giving a type of weight-average, and z-average, to infinite dilution to estimate the molecular weight and the second virial coefficient, average concentration is superior as a concentration variable to original concentration. The plots of observable molecular weight versus average concentration are usually less influenced by the choice of the sedimentation parameter, especially of rotor speed. The general expressions are applied to a few special cases; monodisperse polymer, polydisperse homologous polymer, and polymer blend. The results are compared with experiments on a monodisperse, polystyrene, a polydisperse poly(methyl methacrylate), and a mixture of the two polymers, all in 2-butanone at 25°C. The agreement between the theory and experiments is satisfactory.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090803
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  • 131
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    Apparatus for instantaneously measuring ultraviolet, visible, or infrared dichroism from thin polymer during high-speed stretching (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 2151-2163 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An apparatus has been constructed for following changes in the dichroism of a polymer film undergoing rapid elongation. By means of a rapidly rotating mirror with evenly spaced open sectors, a beam of radiation is passed through the sample and then alternately polarized in the horizontal and vertical direction so that the horizontal and vertical absorbances may be rapidly compared in time as compared with the time of sample elongation (a few milliseconds). The apparatus utilizes reflection optics and a grating monochromator so that measurements may be made by using ultraviolet, visible, or infrared radiation. The transmitted intensity is detected by a photomultiplier or semiconductor infrared device, the output of which is amplified and displayed on an oscilloscope. A temperature-controlled sample chamber is provided. The operation of the apparatus is illustrated by following the change in dichroism of a sample of dehydrohalogenated poly(vinyl chloride) with visible radiation during rapid extension.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160091205
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  • 132
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    Small-angle light scattering from optically anisotropic spheres and disks. Theory and experimental verificationPortions of this paper were presented at the Amherst Forum on Light Scattering by Solid Polymers at the University of Massachusetts, Amherst, Mass., July 1969. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 2165-2246 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The small-angle light scattering (SALS) theory for optically anisotropic spheres and disks is examined in depth. An error is found in the existing sphere equations. The correct form of the equations is identified and then experimentally verified for dilute starch suspensions. Increased concentrations and solid films of starch granules are used to identify the effect of concentration on the scattering envelope. Spherulitic films of isotactic polypropylene, isotactic polystyrene, nylon 610, PET, and nylon 66 are then used to examine different aspects of the SALS theory. Experimental observations are found to agree with the predictions of the correct SALS equations. Disk theory is interrogated and correlated with predictions for spheres. It is found that the predicted patterns from spheres and disks are very similar under identical optical conditions, in contradiction to earlier predictions. A method is developed for identifying the optical sign of spherulites too small to be seen in the optical microscope. This study constitutes a comprehensive examination of SALS theory and includes many other aspects of the phenomena. A catalogue of theoretical Vv SALS patterns from spheres and disks is also included.
    Additional Material: 49 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160091206
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    Multiple phases in filled polymers detected by nuclear spin relaxation studies (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 187-189 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090114
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  • 134
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    Structure and optical activity of a crystalline modification of isotactic poly-(S)-4-methyl-1-hexene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 193-208 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The results of an x-ray and polarimetric study of a crystalline modification (form I) of isotactic poly-(S)-4-methyl-1-hexene are reported and discussed. The x-ray fiber spectra of this polymer are practically indistinguishable from those of isotactic poly-(R)-(S)-4-methyl-1-hexene. Although the crystal structure of the latter can be described on the basis of helices of different screw sense packed in a P4 space group, the crystal structure of poly-(S)-4-methyl-1-hexene is better described on the basis of a P1 space group. The conclusion of the x-ray investigation, that in the crystals of the optically active polymer an equal number of right-handed and left-handed helices must be present, is supported by the polarimetric measurements, which have shown that the polymer in the crystalline form I possesses a rather low rotatory power.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090201
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  • 135
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    Characterization of moisture-cured polyurethane films (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1591-1601 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A series of polyurethanes (PU) prepolymers with NCO/OH ratios of 2.1:1 and 1.9:1 were prepared by reacting hydrogenated methylene di-p-phenyl diisocyanate (HMDI) with triol mixtures of TP740 (molecular weight 740) and TP1540 (molecular weight 1540). Stress-strain (S/S) and swelling equilibrium measurements were performed using thin-film samples prepared by moisture-curing the prepolymer at room temperature. The swollen PU networks gave an S/S curve which is fully described by rubber elasticity theory. The Mooney-Rivlin constant C1 (swollen) was found to increase directly while the molecular weight between crosslinks Mc decreases as the number of branches per cubic centimeter is increased. The solvent - polymer interaction parameter χ determined in benzene was 0.077 + 0.97vr, where vr is the volume fraction of rubber in the swollen network. The crosslink density v′, and Mc were calculated from the relations v′ = pNB and Mc = 0.667 B-1, where B denotes moles of branches per gram, and were found to be in good agreement with v′ and Mc established from S/S and swelling-equilibrium measurements. In calculating v′ and Mc, the water-PU crosslinking reaction at room temperature was assumed to occur mainly through the formation of a urea linkage.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090904
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    Dispersion and polar contributions to surface tension of poly(methylene oxide) and Na-treated polytetrafluoroethylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 363-368 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Average values for dispersion γsd and polar γsd contributions of the solid surface tension γs γsd + γsp for poly(methylene oxide) (PMO) and Na-treated polytetrafluoroethylene (PTFE) are determined by a new computational analysis of wettability data. PMO displays γsd equals; 21.8 ± 0.9 and γsp = 11.5 ± 1.5 dyn/cm while Na-treated PTFE displays γsd = 36.1 ± 3.0 and γsp = 14.5 ± 2.9 dyne/cm. These surfaces present the highest fractional surface polarity ps = γsp/γs = 0.29-0.35 yet encountered for organic polymers or oriented monolayers. These unusual surface tension properties are correlated with surface chemistry and adhesion phenomena.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090210
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    Annealing effects and the α relaxation in drawn polyethylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 369-372 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090211
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    Crystallization of polyethylene at elevated pressures (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 385-406 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The crystallization from the melt of three sharp polyethylene fractions has been studied at 5 kbar. It has been shown that the thickness of so-called extended-chain lamellae is a function of time, temperature, and molecular weight. There is by no means just the fully extended molecular configuration present. Crystallization is qualitatively similar to that of chain-folded crystals at 1 bar, giving an optimum lamellar thickness which increases with time and decreasing supercooling. Fractional crystallization is widespread and is a major cause of disparate lamellar thickness. Isothermal thickening of lamellae during crystallization has been established directly. Morphological detail suggests further that layers can increase their thickness tenfold over their initial size.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090301
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    Occurrence of rippling during the deformation of oriented polyethylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 453-462 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Rippling is another mode, in addition to kink-band formation, by which oriented polyethylene can deform and results in a profuse and irregular waviness in the fibrils. For the medium-density and high-density polyethylenes investigated, rippling tended to occur only at strain rates below about 1 min-1 at 25°C. Above this rate, kink bands tended to form. It is suggested that rippling results from easy slip between the fibrils of the oriented polymers and from the resistance of the fibrils to shortening under a compressive stress. The applied shear stress is reduced by the easy slip to a simple compression along the fibrils, and this distorts the fibril into the series of waves that constitutes rippling. Stress-strain measurements confirm that fibril slip is considerably easier under the rates at which rippling occurs than at the rates at which kink bands form.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090306
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  • 140
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    Dielectric and rheo-optical properties of some ethylene-carbon monoxide copolymers (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 499-515 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Studies were made on films of copolymers of ethylene with 0.5 and 1.0 mole-% carbon monoxide. The carbon monoxide appeared negligibly to affect the degree of crystallinity, melting point, morphology, and dynamic mechanical spectra. Infrared dichroism showed that the orientation of the carbonyl groups was comparable with that of the crystalline CH2 groups and indicated that the carbonyl groups are at least partially within the crystals. This is confirmed by x-ray measurements which indicate an expansion of the a-axis spacing and by an appreciable increase in the height of the α dielectric loss peak which has been assigned to crystalline motion. This α loss peak moves to a lower temperature with increasing carbonyl content, while the γ dielectric loss peak moves to higher temperatures. Activation energies of 25, 35, and 15 kcal/mole for the α, β, and γ peaks, respectively, were independent of carbonyl content and comparable with values for oxidized polyethylene.
    Additional Material: 15 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090309
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    Segmental motion in polyoxymethylenePresented in part at the Meeting of the American Physical Society, Dallas, Texas, March 1970. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 557-567 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The proton spin-lattice relaxation times (T1) of melt-crystallized, solution-crystallized, and solid-state-polymerized polyoxymethylene (POM) were measured between -60 and +150°C. The three types of samples each have a pronounced T1 minimum near room temperature which is a high-frequency manifestation of the γ process. From the quantitative dependence of the relaxation intensity on crystallinity as well as from the absolute magnitude of the relaxation times, it is concluded that the γ process in POM arises from hindered rotation of noncrystalline chain segments. The relation between the relaxation times and the long period indicates that these noncrystalline segments constitute disordered lamellar surface layers, the thickness of which depends on thermal history of the material. The temperature dependence of the motion of the relatively thin surface layers of solution crystallized POM is quite straightforward. The γ process in the bulk-crystallized material involves cooperative motion, however, leading to temperature-dependent kinetic parameters.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090313
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    Nuclear magnetic resonance study of rubber-carbon black interactions (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 829-839 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The mobilities of polymer chain segments in mixtures of rubber and carbon black were investigated by nuclear magnetic resonance. Spin-spin relaxation time (T2) measurements on cis-polybutadiene and ethylene-propylene-diene rubber (EPDM) bound rubbers detected at least two relaxing regions: an immobile region and a relatively free region. The molecular motions in the relatively free region are still constrained compared to those of the pure gum.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090505
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    Adsorption kinetics in the polyethylenimine-cellulose fiber system (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 853-865 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The rate of adsorption of fractionated polyethylenimine (PEI) from water onto regenerated cellulose fibers was studied as a function of the polymer diffusion coefficient. Differences in polymer molecular weight, salt concentration, and pH were employed to vary the diffusion coefficient which was measured independently by a free-diffusion technique. The sorption rate was measured at the same conditions and found to increase with decreasing molecular weight, increasing polymer concentration, decreasing salt concentration, and increasing pH. A simplified rate equation based on diffusion control with Langmuirian adsorption in stirred solution was developed by utilizing the concept of a Nernst diffusional film. The equation was successful in predicting the relationship between adsorption rate and diffusion coefficient for most cases studied. It was found, however, that a very large barrier to mass transfer retards the adsorption rate. For the system studied it was concluded that this barrier is a result of diffusion into and subsequent adsorption onto the internal porous structure of the cellulose.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090507
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  • 144
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    New approach to the effects of pressure dependence on sedimentation velocity experiments (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 939-957 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A theory is developed for sedimentation velocity experiments when the sedimentation coefficient sp depends on pressure P as sp/so = (1 + γP)-1, where γ is a constant. In contrast to the more usually analyzed from sp/so = 1 - γP, this model does not lead, in extreme cases, to a negative sedimentation rate. A theory is presented for homogeneous macromolecules sedimenting with no diffusion. It leads to estimations of so and γ from a knowledge of the point of maximum concentration gradient as a function of time. Results of these calculations are compared with accurate numerical solutions of the Lamm equation with diffusion included.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090513
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  • 145
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    Optical anisotropy of polymer chains and Markov processes. I. Polyethylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 961-981 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A study of the average molecular optical anisotropy 〈γ2〉 of tetrahedral lattice polyethylene chains of any length has been carried out by using Markov processes. The results of this treatment include simplified models of polymer chains, as well as more elaborate models, which are in current use.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090601
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  • 146
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    Structural phenomena in polymers arising at low temperatures and by the action of high forcesPaper presented as a Section Lecture at the 22nd International Congress of Pure First and Applied Chemistry, Sydney, Australia, 1969. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1061-1081 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: New structural phenomena which can be produced in polymers at low temperatures or by the action of high forces are described and discussed. Experimental evidence supports the argument that the deformation of polymers can develop not only as a result of conformational changes of the macromolecules proper but also by transformation of more complex structural formations. The consequence of this phenomenon is the possibility of large deformations far below the glass-transition temperature in a crystalline polymer with well-developed supermolecular structure. This type of deformation takes place without molecular orientation. Another phenomenon discussed is the sharp change of supermolecular structure in crystalline polymers caused by the action of a shock wave. These effects ought to be connected with an energetic rather than entropic deformation mechanism because the transformations occur at a supermolecular level. Thus, there can be two extreme types of deformation processes: the well-known conformation changes that occur at a molecular level, and the deformation of supermolecular structures. Examples of the pure form of the latter type of mechanism obtained under extreme conditions are given.
    Additional Material: 17 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090605
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  • 147
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    Low-angle light-scattering equations for polymer spherulites (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1147-1148 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090610
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  • 148
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    Morphological effects on formation and behavior of radicals in γ-irradiated polyethylene single crystals (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1173-1190 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polyethylene single crystals differing in lamellar thickness, both as-grown and annealed with different lamellar thickness, were irradiated by γ-rays to a dose of about 107 rad at liquid nitrogen temperature in vacuo, and then ESR measurements were made. It was found for the as-grown crystals that alkyl radicals were concentrated at the crystal surface. For the annealed crystals it was found that the radical concentration was greater than in the original crystals because of an increase in disorder with annealing. By assuming that the crystals form blocks upon annealing and that the surface and the interior of the blocks have the same trapping capacities for radicals as in the original crystals, the dependence of the size of the blocks upon variation in annealing temperature and the original lamellar thickness was estimated. This estimate is supported by the theory of the thickening process of single crystals. Two types of radical reactions with different reaction rates were found to occur simultaneously at room temperature. The rapid process was independent of lamellar thickness and was related to the reaction of radicals mainly in the surface region and the defects within the crystals. The slow process was strongly dependent on the lamellar thickness (i.e., the reaction rate was much depressed as the lamellar thickness was increased) and was inferred to be closely related to molecular motions manifested in viscoelastic measurements by the crystalline dispersion αc.
    Additional Material: 15 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090702
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  • 149
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    Crystal deformation during the growth of kink bands in oriented polyethylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1255-1269 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: When oriented polyethylene is sheared at an angle to the orientation axis, kink bands often develop and grow, with a resulting change of the crystalline orientation. Beside the crystalline reorientation, the following changes within the kink bands have been observed with wide-angle x-rays: (a) partial transformation to a monoclinic from the normal orthorhombic unit cell; (b) partial alignment of the orthorhombic b axes; (c) rotation of the orthorhombic c axes of a fraction of the crystals around the kinks by an extra 40 to 60° beyond that of the fibrils; and (d) misalignment of the orthorhombic (hk0) planes by a few degrees. These results are suggested to arise, at least in part, from crystal flattening and from crystal twinning or pseudotwinning on planes intersecting the molecular axes.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090707
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  • 150
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    Study of low-frequency motions of extended chains in polyethylene by Neutron inelastic scattering (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1219-1234 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The low-frequency skeletal and intermolecular modes (below 900 cm-1) have been studied for a sample of “as-polymerized” Ziegler-Natta polyethylene for which extended-chain conformations have been proposed. These results have been compared with data from a sample of stirred-solution-crystallized polyethylene and with previous measurements for highly crystalline samples of folded-chain polyethylene. Measurements were also made of the temperature dependence of these modes for the as-polymerized material and of the polarization dependence of these modes for an oriented sample of solution-stirred polyethylene. In the neutron spectra and the corresponding derived frequency distributions, the observed major “singular” frequencies for both the skeletal and intermolecular modes are in reasonable accord with those previously observed for folded-chain samples of high crystallinity and in Raman measurements. In addition, these frequencies agree with those predicted by theory for the singular frequencies corresponding to the phase-frequency relationships for the skeletal and intermolecular modes of an infinitely extended chain in a crystal. However, in the spectra of the extended-chain materials, these singular frequencies, in general, appear sharpened and enhanced in intensity relative to those for previously reported results on folded-chain polyethylenes; consequently, assignment of their characteristic frequencies is easier. In addition, evidence is presented to show that, for the extended-chain materials, these frequencies broaden less rapidly with increasing temperature, and the corresponding average vibrational amplitudes are smaller than those observed for highly crystalline samples of folded-chain material. It is suggested that in these materials the reduction of the number of chain folds and the increased intramolecular ordering give rise to increased thermal stability of the configurations with regard to segmental rotation and to decreased vibrational amplitudes relative to folded-chain materials. When the aspolymerized materials is preheated above the normal melting point for polyethylene, the neutron spectra revert to those more characteristic of the folded-chain materials, indicating that a relaxation of chain extensions has occurred. However, on the basis of these results, on quantitative estimates of the characteristic relaxation time can be presented. Additional frequencies, besides those predicted by theory for the skeletal and intermolecular modes and those associated with either multiphonon contributions or the presence of chain folds, are observed. The origin of these frequencies remains unclear but may warrant further theoretical consideration.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090704
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    Adhesion of viscoelastic materials to rigid substrates III. Energy criterion for failure (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1344-1344 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090714
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    Polymerization mechanisms and stereosequence distributions: A monomer-dimer model (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 615-632 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A polymerization mechanism in which monomers and dimers add to a growing polymer chain with different rate constants and different stereospecificity is considered. A fraction of the dimers are in isotactic placement internally, and low conversion to polymer is assumed. The stereosequence distribution generated by this monomer-dimer model is calculated and found to be non-Markovian in general. A method of determining kinetic parameters of the mechanism from experimentally obtained placement sequence probabilities and related experimental tests for the applicability of the mechanism are also described. A few ramifications of the general monomer-dimer model are then discussed. A case of special interest is the one in which all the dimers have a single internal tacticity, a model recently proposed by Blumstein, et al., for a polymerization involving the surface of certain aluminosilicate minerals. For the case where all dimers are isotactic, it is found that although the propagation of consecutive syndiotactic placements alone is simple Markovian, the overall stereosequence distribution is non-Markovian. Another special case of interest is the limiting case with dimers only in the feed. This case turns out to correspond to a special case of the cyclopolymerization mechanism proposed previously by Reinmöller and Fox. Although the tacticity distribution of the placements created by the head (or tail) monomer units alone of the dimers is Bernoullian, the composite stereosequence distribution is again non-Markovian.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090405
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    Single crystals of amylose V complexes. III. Crystals with 81 helical configuration (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1471-1481 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Single crystals of amylose V complexes with the 81 helical configuration can be obtained from aqueous solutions of amylose by using α-naphthol as a complexing agent. Morphological observations suggest that the differences in crystallization behavior among the α-naphthol complex and other complexes with alcohols are due to differences in solubility of the complexes in water. Electron diffraction studies indicate a two-dimensional tetragonal unit cell with a = b = 22.9 Å. It is deduced that the space group providing a satisfactory arrangement of two helices is one of the enantiomorphs P41212 and P43212. From x-ray diffraction it was found that the c axis spacing of the α-naphthol complex is equivalent to that in 61 and 71 helical amylose crystals. Consequently, the geometry of the helical configuration requires an integral number of glucose residues per turn. The true helical diameters of the n-butanol, isopropanol, and α-naphthol complexes were calculated from experimental data. The ratio was 6:7:8 and indicated that the helix of the α-naphthol complex has eight glucose residues per turn. The diversity of helical configurations in V amylose crystals is discussed.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090807
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  • 154
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    Vibrational analysis of poly(vinylidene fluoride) (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1517-1523 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A vibrational analysis has been carried out for the two crystalline forms of poly(vinylidene fluoride) (PVF2). The Raman spectrum of the planar form of PVF2 is also reported. The band assignments are made on the basis of the spectral properties including the infrared dichroism and Raman intensities. A force field is derived based on a force constant refinement procedure utilizing the frequency data for both crystal forms.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090811
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  • 155
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    Salt rejection by polymer membranes in reverse osmosis. I. Nonionic polymers (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1537-1551 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An attempt is made to analyze the relationship between salt rejection and water flux of nonionic polymer membranes in reverse osmosis on the basis of the movement of water in the membranes. The salt rejection Rs is a consequence of transport depletion of salt in relation to water flux. The transport depletion can be quantitatively expressed through knowledge of the mode of water transport and by application of free-volume theory to membrane transport phenomena. Water permeation can be characterized by a parameter ω = RTK1/P1v1, K1 denoting hydraulic permeability, P1 diffusive water permeability, v1 the molar volume of water. Thus polymer membranes can be classified in three categories: ω = 1 (diffusion membranes); ω 〉 1 (diffusion-flow membranes); and ω ≫ 1 (flow membranes). Salt rejection Rs can be expressed in terms of P1, the diffusive salt permeability P2, and the effective pressure (Δp - Δπ): \documentclass{article}\pagestyle{empty}\begin{document}$ R_{\rm S} = \{ {\rm \omega } + [P_2 RT/P_1 v_1 (p - {\rm \pi )]\} }^{{\rm - 1}} $\end{document} Experimental results obtained with various hydrophilic polymers are presented as the dependence of Rs on the logarithm of water flux. Good agreement was found between the experimental data and the calculated curve. Excessive swelling of membranes results in bulk flow of water (high ω) with coupled transport of salt. Hence the salt rejection decreases quickly as water flux in creases beyond a threshold value above which water flux can be characterized as bulk flow.
    Additional Material: 4 Ill.
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    Plastic deformation of polyethylene II. Change of mechanical properties during drawing (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 67-83 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The crystallinity, elastic modulus, and tensile strength of samples of various draw ratios together with the true stress - strain curves of high-density polyethylene were determined to establish correlations with morphological changes occurring during deformation. Changes of crystallinity at draw ratios below 5, i.e., constancy during drawing of quenched film and a decrease during drawing of annealed film, are explained by the formation of microfibrils with crystallinity independent of the thermal history of the film. The microfibrils slide past each other at higher draw ratios, generating an increasing number of interfibrillar tie molecules, which is reflected in the increasing number of interfibrillar tie molecules, which is reflected in the increase of crystallinity, elastic modulus, and tensile strength. From the true stress - strain curves, the differential work density for the deformation of the volume element was calculated as a function of the draw ratio. It contains two components which reflect two different mechanisms of deformation. The first component, decreasing with increasing draw ratio, can be associated with the destruction of the original microspherulitic structure; the second one, increasing with increasing draw ratio, can be associated with the deformation of the new fiber structure, i.e., with the sliding motion of the microfibrils formed during the first deformation step.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090106
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    Ethylene-propylene copolymers: Degree of crystallinity and compositionTaken in part from a paper presented at the 1969 Gordon Conference on Elastomers, Colby College, New London, New Hampshire, July 28-August 1, 1969. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 127-142 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: X-ray, differential scanning calorimeter, and density measurements of the degree of crystallinity have been made on ethylene - propylene copolymers which range in composition from 60 to 100 mole-% ethylene. At 23°C the degree of crystallinity was found to vary from zero to approximately 75 wt-% in a regular manner with composition. A systematic difference exists between the x-ray and heat of fusion measurements if a simple two-phase model is assumed in order to calculate the per cent crystallinity from heats of fusion. The apparent heat of fusion of the crystalline fraction detected by the x-ray method is as low as 30 cal/g. This discrepancy increases with comonomer content. It is suggested that large surface or defect energies are present. The broad melting behavior of the samples is also consistent with such a description of the system.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090109
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    Adhesion of viscoelastic materials to rigid substrates. III. Energy criterion for failure (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 659-668 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Measurements are described of the strength of a model adhesive joint subjected to (1) tensile rupture, with the interface containing a small unbonded region of varying size, and (2) pure shear deformation, in the form of a partly unbonded sheet. These, and previous measurements of resistance to peeling separation, are all shown to be consistent with an energy criterion for adhesive failure. The characteristic failure energy per unit area of interface has been determined for the model adhesive material as a function of the effective rate of detachment, over a wide range covering almost the entire spectrum of viscoelastic response. The values obtained are found to increase from levels only slightly higher than thermodynamic considerations would predict, i.e., 102-103 ergs/cm2, at low rates of crack propagation, up to a value of about 106 ergs/cm2 at high rates when the material responds in a glasslike manner. These results suggest that the failure energy has two components: the (reversible) work of adsorption and the (irreversible) work of deformation of the adhesive in effecting separation.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090408
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    Ultrasonic propagation in the vicinity of the glass transition of a poly(carborane siloxane) (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 763-765 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090416
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  • 160
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    Transport properties of methylene chloride in drawn polyethylene as a function of the draw ratio (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1483-1494 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The sorption and diffusion constants of CH2Cl2 at room temperature in quenched polyethylene film drawn at 60°C to different draw ratios λ between 6 and 25 drop drastically between λ = 8 and λ = 9 and then remain nearly constant, dropping only slightly up to λ = 25. Also, the exponential dependence of diffusion constant on concentration of sorbent increases abruptly in the same draw interval and then remains constant at the higher draw ratios. The data may be explained well by a composite madel: a low-permeability fiber structure embedded in a high-permeability spherulitic matrix. As the draw ratio is increased, the initially spherulitic film is gradually transformed into the fiber structure with the transformation being completed between λ = 8 and λ = 9. During subsequent drawing to λ = 25 the mutual arrangement of microfibrils, the basic elements of the fiber structure, changes by longitudinal sliding. However, their transport properties remain nearly constant. The diffusion constant drops a little as a consequence of the increased fraction of tie molecules which reduces the number of unperturbed sorption sites.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090808
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    ESR single-crystal study of radical and radical-pair formation in some γ-irradiated vinyl monomers (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1495-1507 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Single crystals of methyl methacrylate (MMA), methyl acrylate (MA), and acrolein (A) have been prepared by a low-temperature technique. After irradiation with γ-rays at 77°K the paramagnetic species were identified by ESR spectroscopy. MMA gave a seven-line single spectrum from radicals formed by hydrogen addition. The hyperfine coupling constants are slightly anisotropic with a mean value of 22 G. Radical pairs were observed as ΔMs = 1 and ΔMs = 2 transitions; the hyperfine coupling was 11 G. From the strongly anisotropic dipolar interaction, upper limits for the distances between the pair components were calculated to be 5.45 Å and 6.3 Å. MA gave a five-line main spectrum with the same hyperfine coupling values and two radical pairs, one with a distance 5.9 Å between the components. In a there was also a strongly anisotropic interaction. The hyperfine coupling of the ΔMs = 2 transition was 9.8 G. The number of radical pairs compared to the total number of radicals increases only slightly with the radiation dose. This makes it likely that pair formation occurs in the spurs and blobs formed by the γ-radiation. At an increased temperature the radical pairs disappeared; the spectrum of MMA changed to that characteristic of propagating polymer radicals.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.160090809
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    Preparation of indole-3-acrylic acid-vinylurea copolymer (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 829-830 
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    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090325
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    Graft copolymerization of methyl methacrylate onto lignosulfonate by H2O2-Fe(II) redox system. I. Preparation and characterization of the graft copolymer (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 855-866 
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    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Graft copolymerization of methyl methacrylate onto lignosulfonate in aqueous medium was investigated. It was found that the H2O2-Fe(II) redox system is very effective for the grafting (Ea = 4.4 kcal/mole). The H2O2/Fe2+ ratio was the most important factor in the graft copolymerization and characteristics of the resultant graft copolymers. In most cases, polymerization for 100 min at 30°C was enough to obtain 80% conversion and 50-60% grafting efficiency. The resultant polymer mixture was subjected to extraction alternately with acetone and water, and the graft copolymer was isolated free from homopolymer and unreacted lignosulfonate. With increasing H2O2/Fe2+ ratio, the grafting ratio showed a maximum at 4, whereas the yield of graft copolymer and number of poly(methyl methacrylate) branches for every building unit of lignosulfonate increased up to a ratio of 4, both values, however, remaining constant above 4. The graft copolymer obtained for the case H2O2/Fe2+ = 4 consisted of one part of lignosulfonate and five parts of poly(methyl methacrylate). The number of branches in the graft copolymer was 6 × 10-3/OCH3 or one every 167 guaiacyl nuclei.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090402
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    γ-Ray-induced polymerization of α-haloacrylic acids (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 911-918 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The γ-ray induced polymerizations of α-chloroacrylic acid, mp 66°C, and α-bromo-acrylic acid, mp 72°C, were investigated in the temperature range from 35°C to 85°C. An analysis of polymerization kinetics was made, and results were similar to those reported in the literature for other vinyl monomers. On heating of the polymer obtained, elimination of hydrogen halide takes place, and intramolecular lactone formation is observed. The rate of lactone formation of poly(α-chloroacrylic acid) obtained in the solid-state polymerization was found to be higher than that in the liquid state, because a highly isotactic configuration of polymers, tends to be formed in the solid-state polymerization, and elimination of hydrogen chloride is facilitated with an isotactic 52 helix structure.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090407
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  • 165
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    Polyimidazopyrrolones and related polymers. I. Dianhydrides and o-acetamidodiamines (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1045-1070 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Solutions of polyimidazopyrrolone precursors prepared by reaction of tetraamines and dianhydrides in polar solvents tend to crosslink and gel very easily. Substitution of o-acetamidodiamines for the tetraamines gives stable solutions. A study of cure mechanisms by TGA, infrared, and pyrolysis experiments with polymers and model compounds indicates that the acetylated materials are converted cleanly to imides at 150°C. At temperatures above 350°C, structural changes and further polymerization occur, with little imidazopyrrolone formation. Polymers derived from tetraamines cure by multiple mechanisms but finally yield the imidazopyrrolone structure. The acetylated polymers and copolymers give acceptable laminates but poor films.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090418
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  • 166
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    Polyimides based on pyrazinetetracarboxylic dianhydride and some related model compounds (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1117-1138 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A study was made of polyimides based on pyrazinetetracarboxylic dianhydride (PTDA) plus heterocyclic diamines different from the one previously reported by Hirsch. It was postulated that thermal properties might be improved if the diamine portion did not contain the N-N linkage. The results indicate that these heterocyclic-based polyimides are in fact of lower thermal stability and of less molecular weight buildup than their corresponding polypyromellitimides. Thermal failure, outlined by their TGA curves, is shown not to be due to an inherent lack of stability for such polymers, but rather, to synthesis problems arising from both the anhydride and amine precursors. The synthetic problems are twofold: (1) the heterocyclic diamines used in this study display low reactivity; (2) pyrazinecarboxylic acids readily decarboxylate. These conclusions were drawn from a correlation of the relative basicity values of the diamines of consideration and from study of a series of model compounds prepared from an appropriate amine or diamine with PDTA, pyrazinedicarboxylic anhydride, phthalic anhydride, or pyromellitic dianhydride. An accumulation of infrared and mass spectra data for these models relate that the proposed pyrazine polyimides are not of complete polyimide structure, but rather resemble recurring amide-imide units.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090422
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  • 167
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    Anionic graft polymerization of propylene sulfide on cellulose. II. Absorption of iodine, silver, and mercury on the graft polymers (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1481-1492 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The adsorption of iodine, silver nitrate, and mercuric chloride by cellulosic membranes grafted with polypropylene sulfide was investigated. It was found that the grafted polypropylene sulfide adsorbed iodine by complexation from aqueous solution or from gaseous phase. Adsorption from water led to the formation of a complex with molar ratio of I2 to propylene sulfide units of 1, and that while the complex formed from gaseous iodine had a molar ratio I2 to propylene sulfide approaching 2. Most of the sulfide groups participated in complexation. It was found that the complexation of the polysulfide was accompanied by degradation which was attributed to halogenation of the polysulfide at the tertiary carbon atoms. The iodine complex was more stable in water than in organic solvents, where most of the iodine was desorbed. The graft polymers adsorbed also by complexation silver nitrate and mercuric chloride. Adsorption could be described by a Freundlich type isotherm. At low concentrations most of the silver nitrate present in solution was adsorbed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090602
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  • 168
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    Effect of formaldehyde on the cationic polymerization of styrene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1537-1549 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymerization of styrene has been carried out in the presence of formaldehyde at 30°C in benzene solution by using boron trifluoride etherate as a catalyst. The rate of polymerization in the initial stage was accelerated with addition of formaldehyde, while the steady-state rate of polymerization was retarded in the presence of formaldehyde. The acceleration for the rate of polymerization was found only in a short time from the beginning. The steady-state rate of polymerization followed the equation: \documentclass{article}\pagestyle{empty}\begin{document}$ R_{\rm x} = \frac{{ - d[{\rm M}]}} {{dt}} = \frac{{k_1 [{\rm C}]_0 ^2 [{\rm M}]^2 }} {{k_2 + k_3 [{\rm F}]_0 }} $ \end{document} where [C]0 and [F]0 are initial concentrations of catalyst and formaldehyde, [M] is the monomer concentration, and k1, k2, and k3 are constants. It has been assumed that the chain-transfer reaction does not involve formaldehyde itself but rather the reaction products of formaldehyde, such as polystyrene having ethoxy or hydroxymethyl ends. The apparent chain-transfer constant for the added formaldehyde has been determined to be 1.63.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090607
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  • 169
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    Influence of sample size on radiation damage of polyethyleneThis work was supported by the Division of Isotope Development, The United States Atomic Energy Commission. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1765-1767 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090626
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  • 170
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    Synthesis and polymerization of 5-vinyl-2,2′-bithiophene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1785-1785 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090633
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  • 171
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    Thermal decomposition of poly(vinyl chloride) and chlorinated poly(vinyl chloride). I. ESR and TGA studies (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1823-1833 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Significant effort has been made in the past by many workers to investigate the mechanism of thermal decomposition of poly(vinyl chloride) (PVC). The presence and role of free radicals has been controversial in this regard. Our data on PVC and chlorinated PVC systems demonstrate the existence of macroradicals in the early stage of thermal decomposition under inert and oxidative atmospheres. Data from conventional thermogravimetric experiments are used in conjunction with the electron spin resonance findings.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090704
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  • 172
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    Thermal decomposition of poly(vinyl chloride) and chlorinated poly(vinyl chloride). II. Organic analysis (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1921-1935 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A concerted study of poly(vinyl chloride), chlorinated poly(vinyl chloride), and poly(vinylidene chloride) polymers by spectroscopy, thermal analysis, and pyrolysis-gas chromatography resulted in a proposed mechanism for their thermal degradation. Polymer structure with respect to total chlorine content and position was determined, and the influence of these polymer units on certain of the decomposition parameters is presented. Distinguishing differences were obtained for the kinetics of decomposition, reactive macroradical intermediates, and pyrolysis product distributions for these systems. It was determined that chlorinated poly(vinyl chloride) systems with long-chain —CHCI— units were more thermally stable than the unchlorinated precursor, exhibited increasing activation energy for the dehydrochlorination, and produced chlorine-containing macroradical intermediates and chlorinated aromatic pyrolysis products. The poly(vinyl chloride) polymer was relatively less thermally stable, exhibited decreasing activation energy during dehydrochlorination, and produced polyenyl macro-radical intermediates and aromatic pyrolysis products.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090711
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  • 173
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    Radiation-initiated homogeneous grafting of styrene to benzylcellulosePresented at the Fifteenth Canadian High Polymer Forum, Kingston, Ontario, Canada, September 1969. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1901-1919 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Graft copolymers of benzylcellulose and styrene were prepared by direct irradiation of benzylcellulose-styrene solutions with 60Co γ-radiation. The solutions remained homogeneous during irradiation. The amount of styrene grafted to benzylcellulose increased in dilute solutions and was dose-dependent up to 4.0 MR. The graft copolymer consisted of both branched and linear structures with one in every 140-1020 benzylated anhydroglucose units carrying a grafted polystyrene chain. Grafted polystyrene was isolated from the graft copolymer by hydrolysis of the benzylcellulose substrate. The number-average molecular weight and molecular weight distribution of the grafted polystyrene were the same as those for hompolymer formed in the same solution, indicating that the substrate is fully accessible to the monomer and polymerization conditions are uniform throughout the solution during the grafting procedure. The existence of a true graft copolymer was proved by the solubility behavior, intrinsic viscosity, number-average molecular weight, and density-gradient sedimentation of the product of the grafting procedure. Column elution fractionation of the gross products of the grafting procedure failed to isolate the benzylcellulose-styrene copolymer which was eluted with ungrafted benzylcellulose.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090710
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  • 174
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    π-Allyl nickel halide-oxygen system as a catalyst for polymerization of butadiene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1971-1981 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The π-allyl nickel halide-oxygen system was found to be active as catalyst for stereospecific polymerization of butadiene. The catalyst from π-allyl nickel chloride or π-allyl nickel bromide yields the polymer of 90% cis-1,4 content with high activity, whereas the catalyst from π-allyl nickel iodide affords a polymer of 70% or less cis-1,4 content. The catalyst systems can be fractionated into two parts on the basis of solubility in benzene. It is concluded that the catalyst activity originates essentially from the benzene-insoluble nickel complex which is composed of oxygen, halogen, σ-allyl group, and nickel. The structure of growing polymer terminal is discussed in relation to the mechanism of the stereospecific polymerization.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090715
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  • 175
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    Determination of chlorine distribution in chlorosulfonated polyethylenes by high-resolution NMR spectroscopy (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 2051-2061 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High-resolution proton magnetic resonance (NMR) spectroscopy was used to determine the sequence distribution of chlorines in elastomeric chlorosulfonated polyethylenes. The determination is based on measuring the relative amounts of methylene groups that are α, β, and γ (or greater) from chlorine containing groups (CHCl groups) in chlorosulfonated polyethylenes. The results obtained from the NMR examination at 220 MHz were compared with the theoretical predictions based on the statistics of substitution polymers. The comparison showed that polyethylenes chlorosulfonated by a solution reaction with gaseous chlorine and sulfur dioxide show a random chlorine distribution.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090721
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  • 176
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    Polymerization of the N-carboxy anhydrides of alloisoleucinePresented to the International Symposium on Macromolecular Chemistry, Budapest, Hungary, 1969. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 2079-2083 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090724
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  • 177
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    Diffusion and permeation of gases through nitroso rubber (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 2105-2107 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090729
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  • 178
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    Synthesis and thermal degradation of some ferrocene-containing polyazines and poly-schiff bases (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 2137-2146 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of ferrocene-containing polymeric azines and polymeric Schiff bases have been synthesized by means of acid-catalyzed solution polycondensations. The molecular structures of the polymers synthesized have been determined, and information concerning their thermal behavior has been obtained. Comparative thermal stabilities of the products of polymerization of aliphatic and aromatic diamines with 1,1′-diformylferrocene and 1,1′-diacetylferrocene were investigated by thermogravimetric analysis both in air and in an inert atmosphere. In the inert atmosphere, initial weight loss due to thermal stress did not occur below 300°C in all cases, and in many cases 50-70% residue of polymer sample remained at 700°C. The use of a fluorinated diamine led to the synthesis of a polymer which did not exhibit any significant enhancement of thermal properties. Investigation of the polymer products by direct inlet mass spectroscopy led to the observation that several of the systems contained significant amounts of cyclic dimers, although linear polymers were the major products in most cases. Extraction of the cyclic dimers followed by molecular weight determination by vapor phase osmometry confirmed their molecular structures.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090803
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  • 179
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    Effects of nonionic surfactants on seeded polymerizations (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 81-89 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate of polymerization of vinyl acetate in systems containing poly(vinyl acetate) seed particles was investigated. A significant reduction in rate was observed when nonionic surfactants were adsorbed onto the particles prior to polymerization. The molecular weight of the poly(ethylene oxide) moieties in the surfactants was varied over two decades. The diminution in rate was relatively insensitive to this molecular weight variation, at least for higher molecular weights (≥20,000). A minimum in the rate was apparent at lower molecular weights. No new nucleation was detectable in any of these systems. The results have been interpreted in terms of two properties of the dissolved poly(ethylene oxide) layers through which the oligomeric free radicals must diffuse in order to reach the major loci of polymerization inside the particles. These two properties, the effective thickness of the dissolved poly(ethylene oxide) layer and its average microscopic viscosity, are expected theoretically to be approximately self-compensating when the molecular weight is varied.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090107
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  • 180
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    Free-radical homopolymerization and copolymerization of vinylferrocene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 651-662 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The benzene solution homopolymerization of vinylferrocene, initiated by azobisisobutyronitrile, gave a series of benzene-soluble homopolymers. Thus, free-radical copolymerization studies were performed with styrene, methyl acrylate, methyl methacrylate, acrylonitrile, vinyl acetate, and isoprene in benzene. With the exception of vinyl acetate and isoprene, which did not give copolymers with vinylferrocene under these conditions, smooth production of copolymers occurred. The relative reactivity ratios, r1 and r2, were obtained for vinylferrocene-styrene copolymerizations by using the curve-fitting method for the differential form of the copolymer equation, by the Fineman-Ross technique, and by computer fitting of the integrated form of the copolymer equations applied to higher conversion copolymerizations. In styrene (M2) copolymerizations, the curve-fitting and Fineman-Ross methods both gave r1 = 0.08, r2 = 2.50, while the integration method gave r1 = 0.097, r2 = 2.91. Application of the integration method to methyl acrylate and methyl methacrylate (M2) gave values of r1 = 0.82, r2 = 0.63; r1 = 0.52, r2 = 1.22, respectively. The curve-fitting method gave r1 = 0.15, r2 = 0.16 for acrylonitrile (M2) copolymerizations. From styrene copolymerizations, vinylferrocene exhibited values of Q = 0.145 and e = 0.47.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.150090307
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    Use of phosphite amides in the synthesis of polyamides (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 701-716 
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    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation of polyamides by the phosphite amide procedure was investigated. The yield of amidation was determined in the reaction of diethyl- or o-phenylenephosphite derivatives of piperidine, piperazine, or trans-2,5-dimethylpiperazine with either mono- or dicarboxylic acids. Higher yields were obtained by using diethyl phosphite derivatives; however, for both types of derivatives the yields were never greater than 90%. Only low molecular weight polymers could be obtained under optimum reaction conditions. In the polycondensation of (+)-trans-1,3-cyclohexanedicarboxylic acid or (+)-trans-1,2-cyclohexanedicarboxylic acid with phosphite derivatives of either piperazine or trans-2,5-dimethylpiperazine, the optical rotation of the polymers was lower than the rotation of the corresponding polyamides prepared by the interfacial condensation procedure with dicarboxylic acid chlorides. It was shown that an intermediate mixed anhydride was formed during the amidation reaction. This may account for the observed racemization.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/pol.1971.150090311
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  • 182
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    Polycondensation of resin-acid dimers with diamines (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 801-804 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090318
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    Aminimides. XII. Synthesis, homo- and copolymerization studies of trialkylamine N-acryloyl or N-methacryloyl glycinimides and β-aminopropanimidesPaper presented in part to the Division of Polymer Chemistry, 161st National Meeting, American Chemical Society, Los Angeles, March 1971. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 3453-3470 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some representative examples of a new family of aminimide monomers, i.e., trialkylamine N-acryloyl or N-methacryloyl glycinimides and β-aminopropanimides have been prepared and studied. These are the first examples of a possible large family of primary aminimide monomers. With radical initiators, the acryloyl and monosubstituted methacryloyl monomers readily homopolymerize. The disubstituted methacryloyl aminimides do not homopolymerize under the same conditions. All of the new monomers copolymerize with styrene, methyl methacrylate, and n-butyl acrylate. The various polymers were characterized by IR, DTA, TGA, GPC and inherent viscosities. When heated (160°C) the polymers liberate amine and crosslink in the presence of active hydrogen moieties to give resins with carbamate, urea, allophonate, etc., residues. When no active hydrogens are available during heating, polymers can be prepared with pendent primary isocyanate groups. This preliminary work shows these monomers to be highly useful for preparing a wide variety of reactive copolymers.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150091204
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    Optical rotatory properties of synthetic polymers. I. Optical inversion of poly(propylene oxide) (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 3529-3540 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (+)-1,2-Diethoxypropane, a model diether for the repeating unit of poly(propylene oxide), was prepared, and its behavior in solutions regarding optical rotatory dispersion and proton magnetic resonance was compared with those of the polymer. It was found that the model compound and the poly(propylene oxide) show essentially the same optical properties in solutions. By using the Brewster model of optical activity, it was concluded that the solvation of the polymer may well modify the polarizability of the optically active species to cause changes in the order of the polarizabilities of four atoms directly attached to the asymmetric carbon atom. The explanation is shown to be applicable also to some of related polymers.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150091210
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  • 185
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    Radiation chemistry of aqueous poly(ethylene oxide) solutions. II. Highly purified samples (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 3555-3561 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The radiation chemistry of highly purified, rigorously degassed aqueous solutions of poly(ethylene oxide) is markedly different from solutions not so treated. Gelation doses are lower in the purified samples by almost two orders of magnitude. Degradation is unimportant in dilute solutions. The very broad molecular weight distribution as well as the very high molecular weight of these polymers makes the interpretation of the results difficult. Neither gel dose measurements nor solubility measurements give valid crosslinking yields. The crosslinking yield is highly concentration-dependent.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150091213
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  • 186
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    Thermal degradation of poly(alkyl acrylates). II. Primary esters: Ethyl, n-propyl, n-butyl, and 2-ethylhexyl (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 931-948 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantitative analyses of the products of thermal degradation of poly(ethyl acrylate), poly(n-propyl acrylate), poly(n-butyl acrylate) and poly(2-ethylhexyl acrylate) have been made, principally by the combined application of GLC and mass and infrared spectroscopy. Data are recorded in mass balance tables. The major gaseous products are carbon dioxide and the olefin corresponding to the ester group. The minor gaseous products include the corresponding alkane, the alkane/olefin ratio being of the order of 10-2-10-3, and traces of carbon monoxide and hydrogen. The alcohol corresponding to the alkyl group is the major liquid product but there are also traces of monomer and the corresponding methacrylate. Alcohol production exhibits autocatalytic properties. The chain fragment fractions of the products are colored yellow and have average chain lengths of 3.2, 3.3, 3.6, and 5.6 for the ethyl, n-propyl, n-butyl and 2-ethylhexyl esters, respectively. The infrared spectra are similar to those of the parent polymers but with well defined differences. Insolubility develops in the ethyl, n-propyl, and n-butyl esters, but the residual material from poly(2-ethylhexyl acrylate) remains soluble even at very advanced stages of degradation. All of these products and reaction characteristics are accounted for in terms of radical reactions with a unique initiation step.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090409
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  • 187
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    Collision between polymeric radicals for termination rate constants (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 577-580 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The motion of each polymeric radical during a collision between the polymeric radicals with the same radius is treated as completely random motion. The result obtained is: kt = 0.250ks (where kt is the chain-termination rate constant and ks is the reaction rate constant between radical chain ends). On taking the motion of the primary radical during a collision between a primary radical and a large polymeric radical to be completely random, the result obtained is: kti = 0.250ksi (where kti is the primary radical termination rate constant and ksi is the reaction rate constant between primary radical and radical chain end). On substituting ks for ksi in the second equation, the rate constant obtained becomes the chain termination rate constant between the very small polymeric radical and the very large polymeric radical, and identical to the former equation. This identity indicates that the effect of the difference of the size of the polymeric radicals on the collision process relating to the chain termination rate constant should not be large.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090301
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  • 188
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    Structure and reactivity of α,β-unsaturated ethers. XIII. Cationic copolymerization and acid-catalyzed hydrolysis of 1,2-dialkoxyethylenes (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 629-638 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cationic copolymerizations of geometrical isomers of 1,2-dimethoxy- and 1,2-diethoxyethylenes with vinyl isobutyl ether as a reference monomer have been carried out in methylene chloride at -70° using boron trifluoride etherate as catalyst. The kinetics of the acid-catalyzed hydrolysis of these ethers has also been investigated in 80% aqueous dioxane, in order to compare the results with the polymerizabilities. It has been found that the cis ethers are ca. four times as reactive as their trans isomers in both reactions. On the other hand, it has been proved that a β-alkoxyl substitution reduces the hydrolysis reactivity of vinyl alkyl ethers by a factor of ca. 10-3 while it even enchances the cationic polymerizability. These contrasting results are interpretable from the nature of the transition states which are different for the two reactions.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090305
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  • 189
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    Elastomers from the copolymerization of conjugated dienes and styrenes containing chlorine (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 677-689 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymers of 1,3-butadiene and o- and p-chlorostyrenes have been made by use of alkyllithium initiators. These copolymers have a uniform distribution of the chlorostyrene along the chain, suggesting that the reactivity ratio of 1,3-butadiene and chlorostyrene is close to unity.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090309
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  • 190
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    NMR identification of C11 to C40 branched hydrocarbons derived from the decomposition of polyisobutylene (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 717-746 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The composition of nonvolatile fluids obtained from thermally cracking and hydrogenating polyisobutylene was determined by using a combination of gas chromatography and nuclear magnetic resonance spectroscopy (NMR). This work involved the separation and characterization of a homologous series, C11-C40, of sixteen branched hydrocarbon species consisting of repeating isobutylene structures. As a result of this investigation, useful correlations between NMR spectra and molecular structure for highly branched hydrocarbons were developed. The data demonstrate that these hydrocarbons are unique species characterized by “crowded” and sterically hindered geminal methyl and isolated methylene groups. NMR solvent shift studies in benzene solutions indicate that it is possible to differentiate between maximally crowded geminal methyl groups and between maximally crowded methylene groups in these structures. Results of the benzene-induced solvent effects are discussed with respect to the stereochemistry of these molecules and related to existing solvent shift data. These results suggest that these hydrocarbons are polar or nearly polar materials. Successive losses of isobutylene units from stabilized tertiary radicals can account for the formation of the major species identified in these fluids. Higher carbon numbered species have lower refractive indices and densities and higher molal volumes than predicted by calculations.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090312
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  • 191
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    Ladder pyrrolone structures with anthraquinone recurring units (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 691-700 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,2,4,5-Tetraaminoanthraquinone and 1,4,5,8-naphthalene-tetracarboxylic acid dianhydride react in dimethylacetamide to give a tetrameric prepolymer with balanced endgroups of anhydride and diamine. When this prepolymer is carefully treated with polyphosphoric acid at elevated temperature it is converted to a soluble polypyrrolone type structure with an inherent viscosity of 2.3-2.7. Polymers of this molecular weight can be wet-spun into pliable fibers from methanesulfonic acid. The TGA curve in air shows little weight loss below 550°C. The polymer can also be solubilized by reduction with sodium dithionite in alkaline aqueous dimethyl sulfoxide.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090310
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  • 192
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    Dependence of reactivity of propagation centers of oxide catalysts for ethylene polymerization on catalyst composition and activation conditionsPresented to the Symposium on Macromolecular Chemistry, Budapest, August 1969. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 771-784 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The propagation rate constant Kp was used as a measure of reactivity of propagation centers in ethylene polymerization with oxide catalysts. This constant was determined by a radiotracer quenching technique for oxide catalysts of different compositions and activation conditions. For catalysts based on various transition metal oxides, an increase of Kp was observed in the series W 〈 Mo 〈 Cr and V 〈 Cr. In the case of chromium oxide catalyst it was shown that Kp value does not depend on the content of the transition metal in a catalyst. A change of propagation center reactivity was found when oxides of different composition (SiO2, Al2O3, ZrO2, TiO2) were used as supports. An increase of the vacuum activation temperature of a catalyst results in increasing Kp. Pretreatment of catalyst with different reducing agents (SO2, CO2, NH3, HCN) results in the change of Kp value in comparison in comparison with the catalyst activated by the vacuum treatment only. The data obtained on the variation of the reactivity of the propagation centers permit one to draw a conclusion about the composition of surface compounds as acitve centers of the oxide polymerization catalysts.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090315
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  • 193
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    Photo-graft polymerization of methyl methacrylate onto styrene-vinylbenzophenone copolymer (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 809-812 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090320
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  • 194
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    Polymer containing anthraquinone quinoxaline units: Polypyrrolones (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 831-831 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090327
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  • 195
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    Electroinitiated polymerization of vinylic monomers in polar systems. I. Contribution of the electrolysis of methanol to free-radical polymerization (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1375-1386 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electrolytic polymerization of acrylates and methacrylates in methanol solution containing lithium acetate as electrolyte was investigated under currents ranging from 10 to 100 mA. Polymer yield increases up to a limiting current value, beyond which it decreases. This abnormal behavior is discussed. A free-radical mechanism is suggested.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.150090518
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  • 196
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    Pyrolysis-gas chromatographic analysis of poly(vinyl chloride). II. In situ absorption of HCl during pyrolysis and combustion of PVC (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1387-1400 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A pyrolysis-gas chromatographic technique for measuring the amount of hydrogen chloride released during the high temperature pyrolysis of poly(vinyl chloride) resins, plastisols, copolymers and compounds containing inert fillers has been developed. The technique, which is also applicable to the analysis of chlorinated polyethylene and chlorinated poly(vinyl chloride), is based on the use of a standard precursor of HCl, poly(vinyl chloride) homopolymer. The analysis has been successfully used to measure the degree of in situ absorption of HCl during pyrolysis by certain basic fillers [K2CO3, CaCO3, CaO, MgO, Al(OH)3, Na2CO3, Al2O3 and LiOH] dispersed in a poly(vinyl chloride)-o-dioctyl phthalate matrix. Combustion of a number of combustion residues (chloride determination) revealed that the amount of HCl absorbed by the basic filler was independent of the method of degradation (pyrolysis or combustion). Flammability measurements of those matrices having the same composition indicate that in situ absorption of HCl during combustion has little effect on the overall flammability of these materials.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.150090519
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  • 197
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    Synthetic thermally reversible gel systems. VII (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 959-973 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymethacrylylglycinamides (PMG), like polyacrylylglycinamides (PAG), form thermally reversible aqueous gels, but higher molecular weights and/or concentrations are required and the melting points of the gels are lower. The heats of crosslinking for aqueous PMG gels fall in the range of -5 to -10 kcal/mole of crosslinks, the same as for aqueous PAG gels, implying that the crosslinks are chemically similar. PMG and PAG are incompatible with each other but both are individually compatible with some types of gelatin. The solubilities of PMG and PAG are similar. Various reagents, however, affect PMG and PAG gels in quite different manners. Aqueous PMG solutions, just outside conditions required for gelation, are rheopectic. Intrinsic viscosities [η] of PMG in 2M NaCNS are about 2.5 times those in water. The Huggins' k′ value for PMG in 2M NaCNS has a value of 0.39-0.40, and both it and [η] are essentially temperature-independent over the range 25-45°C. In water at 25°C for PMG, k′ has an average value of about 1.4. With increasing temperature, for H2O, there is a considerable increase in [η] which is accompanied by a decrease in the value of k′. Osmotic molecular weight measurements on unfractionated PMG in H2O at 40°C yield π/c versus c plots having essentially zero slope, implying a value of close to zero for the second virial coefficient, a value of about 0.5 for the polymer-solvent interaction parameter, and a condition close to a θ condition. An approximate viscosity-Mn relationship for polydisperse PMG is [η]2M NaCNS, 25deg;C = 1.7 × 10-8 Mn1.5. The low value of K and high value of the exponent do not result from large differences in polydispersity but rather from a stiff, rodlike configuration in solution. This steric hindrance to rotation also manifests itself in the extreme brittleness of PMG films and in a ΔHp for homopolymerization of only -6 kcal/-mole. The infrared spectra of MG monomer and PMG are recorded as well as the density and refractive index for PMG. PMG has a glass transition at 226°C by DTA and by TGA, thermal decomposition sets in at about 300°C. From copolymerization with acrylic acid, values of 1.66 and +0.06, respectively, were obtained for the resonance factor Q and the electrical factor e for MG monomer.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.150090411
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    Radiation-induced crosslinking of cellulose with acroleinPaper presented at IUPAC meeting in Macromolecular Chemistry, Budapest, August 26, 1969. (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 1013-1025 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The process of radiation-induced crosslinking of cellulose is found to be highly influenced by radiation dosage and dose as well as by the solvents used and their concentration. The best crease resistance has been obtained in cases when cellulose is crosslinked with acrolein in the vapor phase. Moreover, the process is entirely radiation-induced and practically no homopolymer is formed. Chemical analysis and investigations of infrared spectra indicate that crosslinking proceeds on vinyl as well as on aldehyde groups of acrolein.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090416
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  • 199
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    Alternating copolymerization of carbonyl sulfide with aziridines (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 13-25 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of carbonyl sulfide with aziridines such as ethylenimine, propylenimine, and N-ethylethylenimine was studied in various organic solvents. The copolymerizations occurred easily without the addition of any catalyst and gave white powdery crystalline copolymers. The copolymers produced were insoluble in many organic solvents, but soluble in p-chlorophenol and dimethyl sulfoxide. The elementary analyses and the infrared spectra showed that alternating copolymers which have a thiourethane structure were produced. In the copolymerization of carbonyl sulfide with ethylenimine, both the polymer yield and the molecular weight of the resulting polymer increased with the use of a solvent having a higher dielectric constant, and also with an increase in the ratio of carbonyl sulfide to imine in the feed. The rate of copolymerization of carbonyl sulfide with aziridines was in the order of ethylenimine 〉 propylenimine 〉 and N-ethylethylenimine. Irradiation of the copolymers improved their thermal properties and increased their melting point.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090102
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  • 200
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    Ziegler polymerization of olefins. IX. Donor effects in metal alkyl-free and Ziegler-type stereospecific catalysts (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 617-628 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electron donors, especially trialkylamines and azulene, have been examined in aluminum alkyl-, CH3TiCl3- and hydrogen-activated TiCl3 catalysts for the polymerization of propylene to isotactic polymer. A comparison and an evaluation were made with findings which were established earlier with zinc alkyl-based TiCl3 catalysts. We find that the donor, when it is present in low concentrations in all of the above catalysts, can inactivate preferentially the less stereoregulating sites. In this way the isotactic content and the molecular weight of the polymer are increased, but only at the expense of a lower catalyst activity. The addition of hydrogen to the TiCl3-donor catalyst at -78°C produced a threefold effect: (1) the activity of the catalyst was increased about 5 to 15 times and higher, (2) the polypropylene formed with this more active catalyst was more isotactic (ca. 10-15%), and (3) the polymer had a lower molecular weight. It is proposed that the increase in catalyst activity was due to the generation of Ti-H bonds to which propylene molecules then added, the Ti-H bonds thus being transformed into active Ti-C centers.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1971.150090304
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