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  • 1965-1969  (429)
  • 1920-1924
  • 1850-1859
  • 1967  (429)
  • Physics  (429)
  • 101
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 615-622 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Twinned crystals were obtained from fractionated isotactic polypropylene of M̄w = 600,000 by isothermal crystallization at 130°C. for 20 hr. from dilute α-chloronaphthalene solution (0.005 wt.-%). Electron microscopic observations confirm that the molecular chains of polypropylene lamellar crystals extend along the [100] direction while the folding itself occurs within the (010) planes in the monoclinic crystal form. On this basis it is shown that polypropylene forms twinned crystals in which the composition plane is the (1k0) planes. It can be deduced that the formation of twin nucleus occurs before twinning, and then growth occurs from the neighboring region of the crystal boundary by chain folding along the [100] direction.
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  • 102
    Electronic Resource
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 623-631 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The thermodynamic properties of amorphous polyethylene are calculated from a model based on the method of significant structures. The motion of a molecule as a whole is described by the motion of segments, each segment moving independently of all others. It is assumed that on melting, holes appear in the solid lattice and the segments can move into these vacancies, obtaining some gaslike degrees of freedom. The complete frequency distribution for polyethylene is used for the solidlike degrees of freedom, while a corrected classical partition function is used for the gaslike degrees of freedom. The calculated thermodynamic properties are in reasonable agreement with experimentally determined values, assuming each gaslike segment to consist of 20 CH2 groups.
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  • 103
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 633-637 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Equations for the time course of depolymerization of long-chain polymers are derived by the method of randomization of a parameter for the case in which all bonds have equal probability of cleavage. This yields some gain in insight and avoids the necessity for solving systems of differential equations.
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  • 104
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 771-780 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The activity coefficient γNa+, of sodium ion, in aqueous solutions of both isotactic and conventional poly(methacrylic acid) (PMA) has been studies throughout the whole range of degree of neutralization α with a Beckman Na electrode and membrane electrodes. The results show that the fraction of sodium ions bound to isotactic PMA is higher than that bound to conventional (or syndiotactic) PMA over the entire range of α. The binding of divalent counterions (Mg+2, Cu+2, Co+2, and Ni+2) by the two forms of PMA (at α = 0.95) has been evaluated from the release of Na+ ions with the Beckman Na electrode. Turbidimetric determinations of the critical amount of various divalent cation chlorides necessary to bring about precipitation of both isotactic and conventional PMA (at α = 0.95) have also been carried out.
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  • 105
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It is possible to identify three distinct types of polymer adhesion on the basis of the physical state of adhesive and adherend: (1) rubbery polymer-rubbery polymer (R-R adhesion); (2) rubbery polymer-glassy polymer (R-G adhesion); (3) rubbery polymer-nonpolymer (R-S adhesion). Limitations of the diffusion and adsorption theories and their conflicting results are discussed within the framework of the proposed classification. By defining the physical state of the polymer as an adhesive or as an adherend, it is possible to eliminate many of the discrepancies commonly noted in attempted application of the diffusion and adsorption theories. As predicted by the Bueche-Cashin-Debye equation, the diffusion of a polymer into another should be greatly reduced as it changes from the rubbery to the glassy state. For this reason, diffusion, which depends to a great extent on the physical state of the polymer, is actually a limited, selective process. Assuming a 1013 poise bulk viscosity at glass temperature, self-diffusion constants of forty polymers were calculated to be 10-21cm.2/sec. or 10-5A.2/sec. This slow rate of diffusion is unmeasurable and insignificant. Adsorption, which is less dependent on the physical state of the polymer, is more frequently encountered.
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  • 106
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 781-790 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A description is given of a modified cone-and-plate apparatus suitable for the measurement of the streaming birefringence of molten polymers. Some results are given of measurements on a polystyrene and a poly(dimethyl siloxane). Those on polystyrene are compared with solution measurements of the same material by use of the well-known Bueche-Harding parameter. Measurements on the silicone oil have been compared with measurements of the dynamic moduli on the same material, after ascertaining the validity of the stress-optical law for this system as well.
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  • 107
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 791-794 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 108
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 929-938 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Free radicals produced in irradiated polypropylene were studied by the electron spin resonance method. Two temperature regions in which the free radicals decay rapidly were found at around 170°K. and 260°K. The first temperature region corresponds to the γ-dispersion of polypropylene and the second to the β-dispersion. Steric configurations of the free radicals were investigated, and it was concluded that the free radicals trapped in polymer, conformation of which is appreciably twisted from the stable 31-helical structure, decay with small-scale motion of the matrix polymer. The decay of free radicals trapped in polymer of less twisted conformation is associated with the large-scale motion of the matrix polymer. Activation energies of decay were found to be 11 kcal./mole at the lower temperature and 48 kcal./mole at the higher temperature. Time constants of the decay reactions were compared with those for molecular motion of the matrix, with results reflecting the relations of the decay of the polymer radicals to molecular motion in the matrix.
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  • 109
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 939-955 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The deformation of fresh and aged polybutene-1 spherulitic samples has been investigated by microscopic observation, interferometry, studying macroscopic and spherulitic birefringence changes, and study of light-scattering patterns. The spherulite deformation is not affine, the microscopic deformation ratio being less than the macroscopic deformation ratio of the sample and greater in the equatorial regions of the spherulite than in the polar regions. The deviation from affine deformation is less for fresh spherulites than for the aged, where void formation occurs in the equatorial part of the spherulite. This gives rise to large scattering by this part of the spherulite and to form birefringence. The spherulite birefringence and its change with elongation is dependent upon the degree of aging of the sample. The spherulite birefringence is more negative for the aged sample. In the polar regions of the spherulite, this negative birefringence decreases and turns positive at higher elongations, characteristic of a reorientation of the crystals with their optic axes turning from being perpendicular to parallel to the spherulite radius. The spherulite birefringence in the equatorial direction becomes somewhat more negative on stretching a fresh sample but less negative on stretching an aged one. Spherulite distortion and orientation changes are apparent from the light-scattering patterns of films possessing small spherulites. The changes in Vv and Hv scattering patterns upon stretch are different for the fresh and aged samples. The Vv patterns of the fresh samples decrease in intensity with time after stretching a fresh sample with the Hv patterns do not.
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  • 110
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 987-988 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 111
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 957-972 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Drawing of linear polyethylene at 60°C. to an extension ratio of ten drastically reduces the sorption and diffusion of n-pentane, benzene, methylene chloride, and tetrachloroethylene. Methylene chloride was chosen for more detailed study. The sorption is of the normal Fickean type. It is also fully reversible in the temperature range between 25 and 45°C. if the sorbed amount is kept to below 0.5%. At higher concentrations the sample relaxes so that sorption irreversibly increases. The reversible sorption per gram of amorphous component is about 1/6 of that in undrawn polyethylene. The diffusion constant has a larger temperature and concentration dependence than in the undrawn material. At zero concentration the activation energy for diffusion is 34.4 kcal./mole and the diffusion constant at 25°C. is 8 × 10-11 cm.2/sec. as compared with 14.4 kcal./mole and 1.5 × 10-8 cm.2/sec. in undrawn PE. Cold drawing reduces the sorption sites without changing their energy content, but drastically cuts down diffusion and increases the activation energy. A smaller part of the increase of the latter is a consequence of the lower enthalpy of the amorphous material and a larger part is probably due to the increased distance between sorption sites.
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  • 112
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 973-986 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Viscosities of polydimethylsiloxane-pentamer systems were measured over the whole range of concentration. Twelve samples having molecular weights from about 1000 to 5 × 105 were studied. The empirical reduction scheme, plots of log η versus log cM0.68, suggested by Ferry and co-workers is applicable to samples of M̄v ≥ 22,000 over the entire concentration. Such satisfying superposition of data may be attributed to the systems being the homologous mixtures in which glass temperatures of polymers are very low. On the basis of the treatment of Fox and Allen, the effects of the number and weight-average molecular weight on viscosity were examined, and the friction coefficient ζ per chain atom at constant M̄n was calculated over a wide range of M̄n. The value ζ is almost constant (ζ = 7.4 × 10-9 dyne-sec./cm.) in the region of M̄n ≥ Mc, and where otherwise it decreases rapidly with decreasing M̄n. The length of the chainend segment was tentatively calculated.
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  • 113
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 989-989 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 114
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1189-1197 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Integral absorption and desorption of methyl ethyl ketone in atactic polystyrene were studied as functions of film thickness at 25 and 45°C. with concentrations above the critical concentration of the system. In all cases investigated, the reduced absorption and desorption curves for films of different thicknesses did not give a single curve, though the individual absorption and desorption curves appeared to have the shape expected from the Fickian diffusion mechanism. The initial slopes of the reduced curves increased with increasing film thickness for both absorption and desorption. The quantity R0, the value of the reciprocal of the half-time for absorption or desorption extrapolated to zero concentration increment, provides a measure of absorption rate at a given initial concentration. The dependence of R0, on film thickness was almost unaltered in the concentration region concerned at both temperatures. The values of the mutual diffusion coefficient D of the system were calculated by assuming absorption and desorption processes for hypothetical film of infinite thickness to be controlled by the purely Fickian mechanism. The values of D evaluated by this method agreed quite well with those deduced by Kishimoto from steady-state permeation measurements.
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  • 115
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1209-1219 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The intramolecular structure of polyethylene in solution was studied by a high-resolution nuclear magnetic resonance technique. Highly purified n-alkanes (99.5%) from C5H12 to C36H74 were used as its oligomers. The NMR spectra of the polyethylenes (oligomers) are very sensitive to the solvents used. The internal methylene protons of all polyethylenes of various chain length resonance at an identical frequency in carbon tetrachloride. A sharp transition in the NMR spectrum of polyethylene in α-chloronaphthalene at 35°C. was observed at n-C17H36, above which there exist two distinguishable NMR peaks for internal methylene protons, and below which (fewer carbons) only a single peak was seen. The NMR spectra of the internal methylene protons of the polyethylenes (oligomers) taken in benzene are very similar to those taken in pyridine. They are not as easily resolved as those NMR spectra taken in α-chloronaphthalene solutions. The effect of the size of the aromatic solvent molecule on the NMR spectra of the internal methylene protons of the polyethylenes (oligomers) in solutions was demonstrated by using aromatic solvents of various sizes, such as chlorobenzene, α-chloronaphthalene, and 9-chloronathracene. The results indicate that the formation of polymeric structure of the internal methylene groups in the polyethylene chain is very sensitive to the size of the solvent used. The interaction of the solvent with the methylene groups of the polyethylenes varies as a function of chain length; it is stronger for those low member n-alkanes and decreases gradually to an asymptotic value.
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  • 116
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1199-1207 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The microscopic interactions of solvent with the diastereoisomeric units of isotactic and syndiotactic poly(methyl methacrylate) have been studied by high-resolution nuclear magnetic resonance. The changes in chemical shifts in various solvents were compared with those of low molecular weight analogs, methyl acetate, and methyl propionate. These changes are caused mainly by the ring-current effect, which has been found to be larger for the low molecular weight analogs than for the polymer. This is especially true when the protons on the polymer backbone are compared with the corresponding ones in the low molecular weight compounds. As one changes from a chloroform solvent to an aromatic solvent, the displacements of the chemical shifts of the polymer can be expressed as percentages of the corresponding shifts of methyl acetate. For syndiotactic poly(methyl methacrylate) in chlorobenzene, benzene, and α-chloronaphthalene, respectively, the percentages are 82, 93, 75 for ester protons; 35, 29, 17 for the backbone methylene protons; and 18, 6.7, 0 for the backbone α-methyl protons. For isotactic poly(methyl methacrylate) in chlorobenzene and benzene, respectively, the percentages are 71, 76 for the ester protons; 41, 38 for the backbone methylene protons; and 41, 32 for the backbone α-methyl protons. These results are discussed in terms of the local stereochemistry of the polymer systems. The exploitation of procedures of this sort in revealing details of polymer behavior in solution indicates dramatic possibilities for future investigations.
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  • 117
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1235-1247 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An improved method is described for obtaining ultrathin sections of soft polymers for examination in the electron microscope. The method involves cooling the specimens in the temperature range 0 to -160°C. during sectioning. The method has proved particularly useful for the study of microstructure in bulk polymers, especially semi-crystalline materials such as polyethylene. The visibility of some features can be improved by electron staining. Preliminary results obtained on polyethylene and polypropylene are illustrated and discussed.
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  • 118
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 161-169 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyacrylonitrile prepared from γ-irradiated monomer was found to react readily with water over a pressure range of 5,130-34,200 atm. to yield polyacrylamide, while polymer prepared by conventional free-radical catalysts will not hydrolyze under the same conditions. Reaction rates at 85°C. were measured; hydrolysis was extremely rapid at higher temperatures. Results are presented to indicate the radical nature of the reaction. Addition of a free-radical source increases the amount of hydrolysis. Pressure has an effect on the properties of the resulting polyacrylamide.
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  • 119
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Relative changes in polymerization activity of ethylene, propylene, and butene-1 in Ziegler-Natta polymerization were compared by use of TiCl3 samples contaminated with O2 and H2O to various extents. Catalyst depletion varied for the three monomers which supported the existence of different active centers. In butene-1 polymerizations with the system Al(C2H5)2Cl-TiCl3, the formation of active centers involves an irreversible and a reversible (adsorption) reaction, the former pertaining to the formation of Al(C2H5)Cl2 and dependent upon the purity of the TiCl3. The kinetic treatment of the rate curves suggests a mixed order of catalyst deactivation and again points to the importance of Al(C2H5)Cl2.
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  • 120
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 227-230 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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  • 121
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ring-opening polymerizations of cyclic sulfides containing three-, four-, and fivemembered rings were studied. In conjunction with these polymerizations, the relative basicities of the cyclic sulfides employed were also investigated. Polymerizations were effected by the use of phosphorus pentafluoride, boron trifluoride ethyl ether, triethylaluminum, and trimethyloxonium tetrafluoroborate. The resulting polymers were oxidized to the sulfones and differential thermal analyses were obtained on the sulfide polymers as well as the sulfone analogs.
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  • 122
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 339-353 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of styrene was carried out in a cyclohexane solution of natural rubber with stannic chloride. It was found that the grafting copolymerizations of styrene took place as well as the cyclization of rubber. The rate of polymerization of styrene was proportional to the second power of the concentration of styrene and to the concentrations of stannic chloride and natural rubber, respectively. The overall activation energy was about 6 kcal./mole. The percentage grafting increased with increasing concentration of rubber. On the other hand, the grafting efficiency showed the reverse tendency. The percentage grafting could be increased to 150% by the addition of nitrobenzene, a polar solvent.
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  • 123
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 531-536 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The post-irradiation effect of high pressure on the γ-ray-initiated solid-state polymerization of acrylamide has been described. Polymer conversion was found to increase significantly with applied pressure. The molecular weight of polymer increases with pressure.
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  • 124
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 397-398 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 125
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 429-437 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Butadiene polymerizes to cis-1,4 polymer on irregularly stacked, halogen-deficient crystals of cobalt(II) or nickel(II) halides. Halogen is removed from the halides by heating the salts under high vacuum or by photolyzing them in the presence of butadiene. Intrinsic viscosity and solubility of the polymer reach a steady state during polymerization. Cobalt chloride produces polymer of higher intrinsic viscosity than nickel chloride, but polymerization on nickel chloride is faster. Catalytic activity is attributed to the presence of ≤0.1% of nickel and cobalt monohalides in the catalyst.
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  • 126
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 469-480 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mechanism of emulsion polymerization of acrylonitrile has been studied by measuring by dilatometry and electron microscopy the adsorption of monomer into polymer particles and polymerization characteristics such as rate, degree of polymerization, the growth of the particle during polymerization, and the degree of dispersion. In the emulsion polymerization of acrylonitrile, new particles are formed during polymerization at a rate which is proportional to the rate of polymerization and the ratio of unreacted monomer. The total amount of monomer adsorbed on or in the polymer particles is rather small, but the concentration on or in the polymer particles is sufficiently high and proportional to the monomer concentration in aqueous phase. The polymerization proceeds concurrently on or in the polymer particles and in aqueous phase, but the three loci may be continuous rather than discrete. A reaction scheme is introduced here which shows the coexistence of polymerizations on or in the polymer particles and in the aqueous phase.
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  • 127
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 455-468 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The role in and effects on the emulsion polymerization of acrylonitrile (AN) of three different groups of emulsifiers, i.e., low molecular emulsfiers, well-known water-soluble polymers, and new water-soluble polymers containing a sulfonate group have been investigated by a dilatometry and electron microscopy. The major part of this paper concentrates on the study of the relation between the properties of the third group of emulsifiers and emulsion polymerization characteristics of AN such as rate, degree of polymerization, diameter and number of particles, and the degree of dispersion, by adding copolymers of AN and sodium p-styrenesulfonate (SSS) having various compositions. In the emulsion polymerization of AN, the hydrophobic portion of the emulsifier seems to act as a kind of nucleus around which polymer molecules precipitate and particle formation may occur, and the hydrophilic portion stabilizes the polymer particles thus formed. As the number of particles and the degree of dispersion increases, the total surface of the particles increases, which may raise the overall rate of polymerization due mainly to an increased polymerization on the surface of the polymer particles. The well-known emulsifiers may be classified by the properties and ratio of the nucleus portion and the stabilizing portion. The unusual effect of emulsifiers on the degree of polymerization may be explained by a chain-transfer mechanism.
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  • 128
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 521-529 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effects of the addition of various bases to metal acetylacetonate-diethylaluminum chloride catalyst systems were investigated. Generally speaking, the cis content of polybutadiene decreases as the basicity of bases in a homologous series increases. The effects were more prominent for the cobalt and the titanium catalysts than for the nickel and the vanadium catalysts. The effects of the species of halogens on the microstructure of polybutadiene were also discussed. In conclusion, the decrease of the cis content was ascribed to the decrease of the electron density of dπ orbitals of the transition metal atoms.
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  • 129
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    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The AlCl3-initiated cationic polymerization of optically active 1-olefins yields polymers of varying optical rotatory power. Polymers of (+)-3-methyl-1-pentene and (-)-4-methyl-1-hexene prepared between -78 and -55°C. in CH2Cl2 or n-heptane are almost completely optically inactive. Under identical reaction conditions (+)-5-methyl-1-heptene gives polymers of significant optical rotatory power. Alternating SO2copolymers of the same olefins, formed in reactions which proceed through free-radical intermediates, yield optically active products with specific rotations similar to those of low molecular weight analogs. These results are consistent with a cationic polymerization mechanism in which the growing chain undergoes intramolecular hydride shift and the asymmetric carbon atoms are converted into carbonium ions. The data also provide evidence for the lack of rearrangement in free-radical polymerization. By comparing the specific rotations of the cationic and free-radical polymers, the extent of rearrangement during cationic polymerization can be estimated. The calculations show that the 1,2-polymer in cationic poly-3-methyl-1-pentene is less than 2%, the sum of 1,2- and 1,3-polymer in cationic poly-4-methyl-1-hexene is less than 4%, and the sum of 1,2-, 1,3-, and 1,4-polymer in cationic poly-5-methyl-1-heptene is 14-20%.
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  • 130
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 637-649 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of polymerization of the vinyl monomers, acrylamide and methacrylamide, photosensitized by uranyl ions in homogeneous aqueous acid medium was studied systematically. Monochromatic radiation of wavelengths 365, 405, and 436 mμ was used for irradiation. Uranyl perchlorate in aqueous perchloric acid (pH = 0-2) was used as the sensitizer to ensure that only uncomplexed UO22+ ions existed in the solution. Polymerization was found to proceed without any induction period, the steady state being attained in about 10-20 min., and was followed by the measurement of the rate of monomer disappearance by bromine addition method. The chain lengths of the polymers were determined by viscometry. It was observed that there was no change in the initiator concentration, [UO22+], during polymerization. The dependence of the rate of polymerization on variables like light intensity, light absorption fraction by the active species, wavelength, monomer concentration, hydrogen ion concentration, temperature, nature of the acid used (HClO4 and H2SO4), viscosity of the medium etc., were studied. A kinetic reaction scheme is proposed and discussed in the light of the experimental results. Certain rate parameters were calculated. The mechanism of photosensitization by uranyl ions with specific reference to primary photochemical act, initiation of polymerization etc., are discussed.
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  • 131
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 675-676 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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  • 132
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 665-673 
    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 with the VOCl3-AlEt2Br catalyst system at 30°C. in n-hexane reached a maximum at an Al/V molar ratio of 1.5. At this ratio, the rate of polymerization was first-order with respect to catalyst and second-order with respect to monomer concentrations. The apparent activation energy calculated was 6.4 kcal./mole. Diethylzine was found to act as a chain transfer agent. However, the molecular weights of polymers obtained were low. The possibility of bromide-containing catalyst sites acting in the termination reaction has been investigated. The average valence of vanadium is discussed in relation to molecular weights.
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  • 133
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    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Highly crystalline poly(methyl vinyl ether) (PMVE) was produced in toluene in a temperature range of 0 to -20°C. with the use of sulfuric acid-aluminum sulfate complex (SA catalyst). It was found from the NMR spectra that these polymers contained more than 50% of the triad isotactic fraction and the melting point of the unfractionated polymer was about 130°C. However, PMVE containing a large amount of the isotactic fraction was insoluble in nitromethane, so the triad tacticity of highly crystalline PMVE could not be quantitatively determined. The molecular weight of PMVE increased with increasing conversion and increasing polymerization temperature. This behavior is different from that in metal halide catalysts. Also, the stereoregularity of PMVE decreased with increasing monomer concentration. However, addition of a polar solvent and increasing the polymerization temperature had little effect on the stereoregularity of the polymer. The increase in the isotactic fraction at high catalyst concentration and the difference in the monomer composition in the copolymerization of methyl vinyl ether with 2-chloroethyl vinyl ether by SA catalyst from that obtained by BF3·O(C2H5)2 suggest that the absorption of MVE on a catalyst surface is an important step in the propagation step by SA catalyst. The fraction of the triad tacticity calculated from the enantiomorphic catalyst sites model8 coincided with the experimental results. This fact shows that the steric structure of the adding monomer is determined only by the nature of the catalyst irrespective of the nature of a growing chain end. It is concluded, on considering also the results of the previous paper, that completely different factors can control the steric structure of a polymer even for the same monomer when different catalysts are used.
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  • 134
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 917-919 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No Abstract
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  • 135
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 965-974 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On reacting acetylcaprolactam (AcCL) and pyrrolidonate MgBr (Py-) in tetrahydrofuran solution, transacetylation takes place, giving acetylpyrrolidone (AcPy) and caprolactamate MgBr (CL-). The rate constants for the transacetylation reactions were measured at 25°C. Their values in units of liters/mole-second were: \documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{rl} {{\rm AcCL} + {\rm Py}^ - \to {\rm AcPy} + {\rm CL}^ - } \hfill & {k_{{\rm trans}} 1 = 60 \times 10^{ - 2} }\\ {{\rm AcPy} + {\rm CL}^ - \to {\rm AcCL} + {\rm Py}^ - } \hfill & {k_{{\rm trans}} 2 = 60 \times 10^{ - 2} }\\ \end{array} $$\end{document} The rate constants for the addition reactions measured were: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{ll} {{\rm AcPy} + {\rm Py}^ - \to {\rm AcPyPy}^ - } \hfill & {k_{{\rm 11}} = 2.8 \times 10^{ - 2} }\\ {{\rm AcCL} + {\rm CL}^ - \to {\rm AcCLCL}^ - } \hfill & {k_{{\rm 22}} = 0.75 \times 10^{ - 2} }\\ {{\rm AcCL} + {\rm Py}^ - \to {\rm AcCLPy}^ - } \hfill & {k_{{\rm 21}} = 5 \times 10^{ - 2} }\\ {{\rm AcPy} + {\rm CL}^{^ - } \to {\rm AcPyCL}^ - } \hfill & {k_{{\rm 12}} = 2 \times 10^{ - 2} }\\ \end{array} $$\end{document} As the transacetylation is much faster than the addition reaction the copolymer composition should be given by the equation: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{c} [{\rm PyH}]\ {\rm in\ polymer/[CLH]\ in\ polymer}\hfill\\ \qquad\qquad\qquad\qquad\qquad\qquad= K_{\rm trans} K_{\rm acidity} [{\rm PyH}]\ {\rm in\ monomer/[CLH]\ in\ monomer}\\ \end{array} $$\end{document} where Ktrans, the transacetylation equilibrium constant, equals 0.3 while Kacidity reflects the relative acidities of the monomers and its value (from the literature) is about 0.4. Pyrrolidone is, therefore, more reactive than caprolactam in anionic copolymerization by a factor of about 8.
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  • 136
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1033-1047 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymers of styrene with cinnamonitrile, ethyl benzylidenecyanoacetate, and benzylidenemalononitrile were prepared in emulsion with the use of the redox system potassium persulfate-sodium bisulfite. The kinetics of copolymerization as a function of the composition of monomers, of the concentration of emulsifier and initiators, and of temperature was studied. Copolymers of high molecular weight were obtained in good yields.
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  • 137
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1049-1057 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymers of styrene with cinnamonitrile (I), ethyl benzylidenecyanoacetate (II), and benzylidenemalononitrile (III) were prepared in bulk, in suspension, and in emulsion up to high conversion. Their softening points, flexural properties, impact resistance, hardness, and volumetric shrinkage due to polymerization were studied. All three copolymers show improved thermal resistance in comparison to polystyrene, but whereas copolymers styrene-I and styrene-III are inferior to polystyrene in flexural strength and the impact resistance, the copolymer styrene-II is about equal to polystyrene in its flexural properties and impact resistance.
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  • 138
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1101-1106 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Data for the tert-butyl hydroperoxide-initiated polymerization of styrene in dilute benzene solution at 126°C. are presented. These data are discussed in terms of Tobolsky's limiting conversion kinetics. Several rate laws are considered. Simple unimolecular decomposition of the peroxide appears to be unimportant under these conditions, as does solvent interaction.
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  • 139
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1113-1118 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Four new polybenzimidazoles with aryl sulfone linkages between the recurring units have been prepared in order to study their thermal stability and solubility properties. The polymers prepared were high molecular weight materials with good thermal stability.
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  • 140
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1223-1231 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of 4-cyclopentene-1,3-dione (M2) with p-chlorostyrene and vinylidene chloride is reported. The copolymers were prepared in sealed tubes under nitrogen with azobisisobutyronitrile initiator. Infrared absorption bands at 1580 cm.-1 revealed the presence of a highly enolic β-diketone and indicated that copolymerization had occurred. The copolymer compositions were determined from the chlorine analyses and the reactivity ratios were evaluated. The copolymerization with p-chlorostyrene (M1) was highly alternating and provided the reactivity ratios r1 = 0.32 ± 0.06, r2 = 0.02 ± 0.01. Copolymerization with vinylidene chloride (M1) afforded the reactivity ratios r1 = 2.4 ± 0.6, r2 = 0.15 ± 0.05. The Q and e values for the dione (Q = 0.13, e = 1.37), as evaluated from the results of the vinylidene chloride case, agree closely with the previously reported results of copolymerization with methyl methacrylate and acrylonitrile and confirm the general low reactivity of 4-cyclopentene-1,3-dione in nonalternating systems.
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  • 141
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1191-1201 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For the polymerization of n-octadecene-1 with catalysts derived from titanium tetrachloride and triethylaluminum, it has been shown that, in addition to polymerization of the olefin, the formation of isomerized olefin occurs. The latter is predominantly trans-n-octadecene-2 and its formation is favored by increase in Al:Ti mole ratio, in catalyst concentration, and in reaction temperature. It has also been shown that 1,1-disubstituted ethylene is present in the nonpolymeric reaction products. The influence of added trans-n-octadecene-2 or trans-n-octadecene-7 on the polymerization of n-octadecene-1 has been studied, and it is shown that the 2-isomer has the more pronounced effect on polymer yield and intrinsic viscosity. It has also been shown that no significant copolymerization of terminal with nonterminal octenes or octadecenes occurs under these conditions. Results indicate that, in polymerizations of this kind, the interaction of catalyst with isomerized monomer is probably an important factor in determining polymer yield and molecular weight. The isomerization reaction is also of interest as a general preparative method for trans-2-olefins.
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  • 142
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1289-1296 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: From the conversion-composition data of Gruber and Elias, the reactivity ratios of styrene (M1) and methyl methacrylate (M2) were calculated to be r1 = 0.55 ± 0.02 and r2 = 0.58 ± 0.06 at 90°C. The least-squares method was then used on these and literature values at other temperatures to obtain the Arrhenius expressions: In r1 = 0.04736 - (235.45/T), and ln r2 = 0.1183 - (285.36/T). Using literature values for the homopolymerization steps, A11 = 2.2 × 107l./mole-sec., E11 = 7.8 kcal./mole, and A22 = 0.51 × 107 l./mole-sec.-1, E22 = 6.3 kcal./mole, activation energies and frequency factors were then calculated for the cross-polymerization steps: A12 = 2.1 × 107 l./mole-sec., E12 = 7.3 kcal./mole, and A21 = 0.45 × 107 l./mole-sec., E21 = 5.7 kcal./mole.
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  • 143
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1297-1305 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The retardation of acrylonitrile (AN) polymerization by p-toluenesulfinic acid (TSA) in the presence of relatively strong acids has been further investigated. Conductance measurements supported the hypothesis that an ionic complex, presumably RSO2H2+, is obtained by a reaction of the sulfinic acid with a proton. It is postulated that this complex is a chain transfer agent for the observed retardation. On the basis of this assumption, a kinetic scheme was developed involving additional termination steps by the complex. The scheme accounts for the maximum in initial rate observed on increasing the concentration of added sulfonic acid at a constant TSA concentration. It also provides an explanation for the elimination of the autoacceleration in the bulk polymerization of AN when strong acids are added. The orders derived from the kinetic equations are in good agreement with the orders evaluated from the kinetic experiments.
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  • 144
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1313-1326 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Acrylonitrile grafts readily to granular corn starch in aqueous slurry when initiated by hydrogen peroxide plus activator. Prime evidence for grafting lies in the ease of separating PAN from starch in high yield when the initiator is azobisisobutyronitrile rather than peroxide. Grafting efficiencies are determined by extraction with appropriate solvents: dimethylformamide for homo-PAN, and boiling water for ungrafted starch. Grafting efficiencies of PAN range from 78 to 95%, M̄n values for grafted PAN are 4,000 to 90,000, and frequency of attachment of side chains range from 300 to 1100 glucose units per chain. Increasing the monomer level, at fixed initiator concentration, tends to result in longer rather than more frequent side chains. AN behaves much as has been previously found for MMA, but the somewhat more efficient grafting at more frequent intervals and the more nearly uniform distribution of polymer in the starch granule suggest that AN penetrates the starch granule more readily than MMA.
    Additional Material: 6 Ill.
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  • 145
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    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of purified graft copolymers of cellulose acetate and polystyrene, which were prepared and characterized during the course of an earlier investigation, have been used for some initial property studies. Grafts with high molecular weight backbones and low molecular weight side chains and vice versa, and with both side chains and backbones of high and low molecular weights, were prepared. The graft polymers were found to be insoluble in most solvents but soluble in dimethylformamide and pyridine and in mixtures of solvents for each component. Films cast from mixtures of the grafts and homopolymers showed that the grafts were compatible with the homopolymer of the component with a higher molecular weight. A graft copolymer with high molecular weight backbone and side chains was found to be compatible with both homopolymers separately and with a mixture of both across a wide range of compositions. A blend of the high and low molecular weight grafts was also found to be highly compatible with both homopolymers. The permeability, diffusion, and sorption of gases and water vapor in the grafts and in the corresponding homopolymers was also studied. In the case of water vapor, the sorption in cellulose acetate was much higher than in polystyrene whereas the diffusion was much lower. It was found that the graft polymers showed both diffusion and solution behavior closer to that of cellulose acetate, whereas the permeability constants were more intermediate between those of the two homopolymers. The gas permeability and diffusion constants were found to be intermediate between the values obtained with the two homopolymers.
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  • 146
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1395-1405 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chloral and cyclic formals were copolymerized in the presence of acidic catalysts and controlled amounts of water to diols of varying compositions and molecular weights. Cyclic oligomers were formed irreversibly as by-products from the monomers and were also obtained by depolymerization. Condensation of the diols with diisocyanates yielded linear polyurethanes of improved flame resistance.
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  • 147
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1407-1413 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Measurements have been made of the dependence of nuclear magnetic resonance bandwidths of polymers on the degree of crosslinking. Poly(methyl methacrylates) and poly(hexadecyl acrylates) were studied. Three regions of behavior are apparent: (1) in lightly crosslinked materials, bandwidths are quite insensitive to the degree of crosslinking, and the networks behave almost as linear polymers in solution; (2) in moderately crosslinked material, bandwidths are significantly affected by the degree of crosslinking; and (3) in highly crosslinked materials, bandwidths are extremely sensitive to crosslink density, and the polymer peaks become so broad that they disappear almost completely. These results indicate that segmental motion of a polymer in solution is not a function solely of its molecular weight, and that a certain degree of crosslinking is required to restrict polymer motion at the segmental level. The solvent (benzene) peak is always a singlet in swollen poly(methyl methacrylate) systems with swelling ratios up to 6.4 (regions 1 and 2, above) but as the swelling ratio further decreases to 3.5 (region 3), the solvent peak splits into a doublet; this phenomenon may indicate the existence of two different arrangements of solvent molecules in the swollen network, for which interchange is not sufficiently rapid to produce a single line.
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  • 148
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1547-1562 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyethylene has been grafted with maleic anhydride, as proved by the infrared spectra and the properties of the grafted films. The influence of oxygen and a comparison of the effectiveness of benzoyl peroxide and AIBN showed that polyethylene macroradicals are formed through the decomposition of hydroperoxide and peroxide groups. Side chains of poly(maleic anhydride) are formed by a combination of polyethylene macroradicals with those of poly(maleic anhydride). This mechanism of reaction was confirmed by the influence of the amount of film, the initiator and monomer concentrations, and temperature on the percentage of grafting.
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  • 149
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1599-1607 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis and polymerization of N-[1-(1-substituted-2-oxopropyl)]acrylamides and -methacrylamides are described. Seven new monomers were prepared by two kinds of synthetic procedure. The polymerization of these monomers was carried out. Monomer reactivity ratios in the polymerization of these monomers with styrene were determined and the Alfrey-Price Q and e values calculated. The effects of substituents on the reactivities in copolymerization were observed, and an interpretation of the results is given.
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  • 150
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1635-1643 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nuclear magnetic resonance, infrared, and ultraviolet spectroscopy were used to elucidate the structure of oxidized polystyrene. To identify the nuclear magnetic resonance peaks of the degraded polystyrene, deuterated polystyrenes were synthesized and degraded. The primary structure present in the degraded polystyrene was found to be an aromatic carbonyl group. It was shown that this structure was formed regardless of the presence of ultraviolet light and was also present when polystyrene was degraded in carbon tetrachloride solution. When polystyrene was degraded in carbon tetrachloride solution, stable polymeric peroxides were formed in a concentration of 4 peroxide groups for every 1000 styrene units.
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  • 151
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1671-1681 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Turbidimetric titrations have been made on polystyrene and poly-o-chlorostyrene in a series of solvents to deduce the solubility parameters of polymers from the Flory-Huggins interaction parameter χ. The assigned solubility parameter for polystyrene agrees well with the reported values obtained from swelling measurements. Brief discussion of the exceptional behavior in the solvent powers of paraffins is given.
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  • 152
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1699-1704 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 9-Vinyl anthracene has been polymerized by three methods in cationic systems to obtain organic photoconductors. Cationic polymerization catalysts used were titanium tetrachloride and aluminum chloride anhydride. According to the degree of conversion from poly(9-vinyl anthracene) to poly(9,10-dimethylene anthracene) the photosensitivity increased.
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  • 153
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1807-1808 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No Abstract
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  • 154
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1827-1844 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis and cyclocopolymerization with sulfur dioxide of four 1,5- and 1,6-dienes (bicyclopentene, bicyclohexene, dicyclopentenyl ether, and dicyclohexenyl ether) and one tetraene (quartercyclopentene) is described. Under optimum conditions, completely soluble copolymers are obtained from bicyclopentene in high conversions at temperatures down to -39°C. Bicyclohexene also gave soluble copolymers, but in a by far slower reaction and in low conversion. Quartercyclopentene does copolymerize, but as expected, gives only insoluble polymers. The two compounds with 1,6-diallyl ether structure, dicyclopentenyl ether and dicyclohexenyl ether, failed to polymerize. The influence of initiator, temperature, reaction medium, diene concentration, etc., on the properties of the polymers was studied in detail for copolymerizations of bicyclopentene. Only a very limited number of peroxides in unusual large quantities was found to be effective in initiating this copolymerization. The reaction is further limited to a narrow choice of solvents, e.g,. diethyl ether and tetrahydrofuran, in order to obtain soluble products. Polymerization could not be achieved in ethanol, benzene, methylene chloride, dimethyl sulfoxide, and tetramethylene sulfone; excess sulfur dioxide yields only dark and insoluble products. Diene concentrations of below 0.3 wt.-% are normally required to obtain poly(bicyclopentene sulfones) which are soluble in dimethyl sulfoxide, tetramethylene sulfone, or sulfuric acid. Polymerization can be carried out from room temperatures down to -39°C.; optimum results are generally obtained around 0°C. Inherent viscosities of 1.72 (0.5 g./100 ml. dimethyl sulfoxide) have been measured. X-ray diffractions are those of amorphous polymers.
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  • 155
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1881-1887 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of dioxolane initiated by the ∼Si⊕HSO4⊖ ion pair is greatly influenced by water which changes the overall polymerization rate. Particularly great changes are brought about at certain higher conversions (whose values are also a function of an initial concentration of water). The polymerization practically stops at these conversions and the system appears to be close to a monomer - polymer equilibrium. It is shown that the equation Voverall = f([H2O]), which describes the dependence of the overall rate of polymerization on the concentration of water and which was originally derived for the polymerization of trioxane, holds also for the polymerization of dioxolane. The decrease of water concentration during the polymerization was measured and the observed equilibrium was shown to be a kinetic phenomenon.
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  • 156
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1899-1909 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The radiation-induced polymerization of glass-forming systems containing monomers has been investigated. It was found that irradiation below the second-order transition temperature Tg of the systems causes no in-source polymerization but causes a rapid postpolymerization on warming above the Tg after initial irradiation below the Tg. The post-polymerization was followed by differential thermal analysis and ESR spectra. It is caused above the Tg by the release of peroxy radicals trapped below the Tg, and its rate is proportional to the irradiation dose to some extent, often is explosively high, and brings about a remarkably large temperature rise by accumulation of polymerization heat. Irradiation above the Tg causes rapid in-source polymerization which is accelerated by the high viscosity of the monomeric system between Tg and Ts (WLF temperature) compared to crystal or ordinary solution polymerization. The temperature dependence of the in-source polymerization of glassy systems shows a peak between the Tg and Ts which may be the result of competing effects of the rate increase by the decreased termination near Ts and the rate decrease by the decreased propagation caused by the diffusion prevented near the Tg. The degree of polymerization was also investigated. The temperature dependence of the degree of polymerization of the polymers obtained by in-source polymerization shows a peak similar to that of the temperature dependence of conversion. Unusually large values of the Huggins constant k' are noted between Tg and Ts. The degree of polymerization of the polymer obtained by post-polymerized increases with the increase of irradiation dose and the polymerization rate; this may be the result of decreased chain transfer to nonpolymerizable components.
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  • 157
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1911-1925 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of N-vinylcarbazole (VCZ) in ethylene dichloride, acetone, benzene, and dioxane with cupric nitrate, ferric nitrate, and ceric ammonium nitrate as catalyst was studied. In all cases the polymerization seemed to be of a cationic nature, judged by copolymerization with styrene. Electron spin resonance (ESR) spectroscopy was made for the polymerization system and also for a system containing N-ethylcarbazole instead of VCZ. Singlet ESR spectra were observed for all systems containing ceric salt and for some systems containing ferric salt but not for systems containing cupric salt. The ESR spectra indicated the formation of an ion radical by electron transfer between the oxidizing metal salt and the carbazole derivatives. Mechanisms of initiation other than electron transfer were less likely, and it was concluded that the initiation process was most likely to be of the electron transfer type.
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  • 158
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1937-1949 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of tetraoxane with styrene catalyzed by BF3·O(C2H5)2 was studied at 30°C. to determine whether a cyclic monomer can copolymerize with a vinyl monomer. The formation of the copolymer was confirmed by elementary analysis of both benzene-soluble and benzene-insoluble fractions of the polymer obtained. It was found by gas chromatography that a fairly large amount of 4-phenyl-1,3-dioxane and a small amount of trioxane were formed in the present system, in addition to polymers. Roughly a third of the total amount of the monomers reacted was consumed in the formation of methanol-insoluble polymer, a third for 4-phenyl-1,3-dioxane, and another third for trioxane and unknown products which could not be indentified. The formation of these cyclic compounds during the copolymerization may be explained in terms of a back-biting (or intramolecular transacetalization) reaction. The cationic reactivity of tetraoxane was found to be similar to that of styrene on the basis of both the consumption rate of each monomer in the copolymerizing system and the composition of the methanol-insoluble polymer obtained.
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  • 159
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1855-1864 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The NMR spectra of 2,4-DCNP were measured in CCl4, NaCNS-D2O, DMSO-d6, and other solutions. The spectra of the meso form show no significant change with the solvent, but the racemic form shows two kinds of spectra, one of which is observed in a solvent for PAN and the other in a nonsolvent. In the solution, the meso 2,4-DCNP is considered to have two equivalent conformations, TG and G'T, which are the mirror images with each other. The racemic 2,4-DCNP, however, might have predominantly either the TT or GG conformation in CCl4, pyridine, and benzene, while it has the two conformers with almost equal probability in NaCNS-D2O and DMSO-d6. The results obtained from the calculation assuming appropriate constants are in fairly good agreements with the observed spectra of the 2,4-DCNP isomers. The values of chemical shifts and coupling constants used in the calculation correspond to those of PAN which were obtained previously from the analysis of the NMR spectra.
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  • 160
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2005-2012 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kinetic studies on the polymerization of ethyl acrylate have been carried out and the various rate constants and their corresponding activation energies determined.
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  • 161
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    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cationic copolymerization of tetrahydrofuran and propylene oxide was studied in a batch system. Boron fluoride ethyl ether and 1,2-propanediol were used as catalyst - co - catalyst system. Number-average molecular weights M̄n of various copolymers were determined by vapor-pressure osmometry (VPO) and hydroxyl endgroup analysis (OH). The VPO and OH molecular weights differed considerably. To explain the differences, several copolymers were analyzed by gel permeation chromatography (GPC). The chromatograms obtained showed for each copolymer analyzed two peaks, one located in the high molecular weight region, the other in the low molecular weight region. An attempt is made to correlate the results and to show the usefulness of GPC in the characterization of THF - PO copolymers.
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  • 162
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2067-2077 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The meso- and d,l-diastereomers of o-bis(epoxyethyl)benzene have been synthesized and identified. The diastereomers were polymerized by a variety of catalysts to give a polymer which has mainly isochroman recurring units as a result of a cyclopolymerization mechanism. Some features of the polymerization with the triisobutylaluminum catalyst system have been studied. The rates of polymerization of the monomers and the transition temperatures of the resulting polymers have been determined. The results are explained on the basis of a controlled intramolecular propagation and a stereospecific polymerization.
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  • 163
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2133-2146 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Past experimental evidence has indicated that the acid-catalyzed hydrolysis of polysaccharides does not proceed randomly, and it has been suggested that hydrolysis is more rapid for the glycosidic bonds by which the nonreducing endgroups are attached. To test this hypothesis, amylose and cellulose were permethylated and subjected to methanolysis. It was found that in both the methanolysis of tri-O-methylamylose and tri-O-methylcellulose the production of methyl 2,3,4,6-tetra-O-methyl-α,β-D-glucopyranoside was complete before the production of methyl 2,3,6-tri-O-methyl-α,β-D-glucoside was finished. Since the former compound could only come from the original nonreducing end units and the latter from all other units, these results were interpreted as giving support to the idea of a preferential scission of the bonds at the nonreducing ends, even though the release of original end units was not complete until 70-85% of the glycosidic bonds had been cleaved. It was concluded that methanolysis proceeds by a modification of the hydrolysis mechanism and that methanolysis is therefore a poor model for hydrolysis.
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  • 164
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2187-2191 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No. Abstract.
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  • 165
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2199-2201 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No. Abstract.
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  • 166
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2079-2089 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of styrene with VOCl3 in combination with AlEt3 and with Al(i-Bu)3 in n-hexane at 40°C. has been investigated. The rate of polymerization was found to be second order with respect to monomer in both systems. With respect to catalyst the rate of polymerization was first order for VOCl3-AlEt3 and second order for VOCl3-Al(i-Bu)3 systems. The activation energies for VOCl3-AlEt3 and VOCl3-Al(i-Bu)3 systems were 7.37 and 11.25 kcal./mole, respectively. The molecular weight of polystyrene in the AlEt3 system was considerably higher than that in the Al(i-Bu)3 system. The valence of vanadium obtained by a potentiometric method showed that the catalyst sites in the AlEt3 system are different in nature from those in the Al(i-Bu)3 system. The effect of diethylzinc as a chain-transfer agent in the AlEt3 system was also studied.
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  • 167
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2269-2279 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The simultaneous effect of impurities, hite rate of initiation, and chain transfer through the monomer on the size distribution in anionic polymers is investigated. It is assumed that monomer is added to the system containing monofunctional initiators in small doses 80 that there is no accumulation of the monomer or the impurities at any stage of the reaction. Firstly, by using the continuum approach, expressions for the size distribution and the averages are derived for the case when initiation is infinitely fast and chain transfer is absent. These results are compared with those obtained by Oroho and Wenger by a more rigorous analysis, and the adequacy of the simpler results is established. The complexities arising from the finite rate of initiation and chain transfer are considered subsequently. Finally, we describe a procedure for the determination of the initiation and transfer rate constants in terms of propagation rate constant and the fraction of impurities in the monomer supply.
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  • 168
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2229-2245 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The esterification of metal soaps, in the combination of zinc and calcium soaps, on poly(vinyl chloride) (PVC) has been carried out both in liquid and solid phase to determine why the reactivity of zinc soap decreases on addition of calcium soap, improving the long-run heat stability of PVC and causing the well-known synergism. It is suggested as the mechanism of synergism that metal soaps having low ionization-potential values, such as calcium soap, act as ester-exchangers of metal chlorides, such as zinc chloride, which is generated after the stabilization of PVC, and also decrease the reactivity of the zinc soap by forming a complex, as that of zinc soap - calcium soap. If a third material, such as organic ester silane, reacting as ester-exchanger on zinc chloride and preventing the formation of a zinc - calcium soap complex, is added to the system, these compounds have an excellent synergistic effect.
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  • 169
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2458-2459 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 170
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2453-2454 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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  • 171
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2455-2457 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
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  • 172
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2503-2522 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some classes of organometallic catalysts what induce stereospecific polymerization of methacrylonitrile have been found. They include organolithium aluminum compounds of the type LiAlR4, Li[R3AlOAlR2], and Li[R3AlN(R)AlR2], organosodium aluminum compounds of the type NaAlR4, organolithium zinc compounds of the type LiZnR3 and Li2ZnR4, organomagnesium aluminum compounds of the type RMg[AlR4] and Mg[AlR4]2, and organomagnesium compounds containing an Mg—N bond, such as and their related compounds. One of the features of the polymerization with these catalysts was that the crystalline polymers were formed at moderately high temperatures. Total conversion, solubility index, and molecular weight of the polymer increased with increasing polymerization temperature, as observed in the case of polymerization with diethylmagnesium catalyst. Catalysts with an Mg—N bond were found to be highly effective for the stereospecific polymerization. The acetone-insoluble fractions of the polymers gave x-ray diagrams identical to the crystalline polymer produced with diethylmagnesium. This indicates that the acetone-insoluble crystalline polymers produced with these catalysts have an isotactic structure. The viscosity-molecular weight relationship for crystalline polymer was conveniently determined in Cl2CHCOOH at 30°C.; [η] = 2.27 × 10-4 M0.754.
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  • 173
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2557-2562 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 60Co γ-irradiated 2-vinylnaphthalene was obsreved to post-polymerize in the solid phase. Plots of conversion versus time indicated a 14% limiting conversion of monomer to polymer. The post-polymerization was found to be first-order in monomer with an Arrhenius activation energy of 19.0 kcal./mole.
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  • 174
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2595-2615 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,3-Bis[p-(2,3-epoxypropyl)phenyl]tetramethyldisiloxane and its meta isomer were synthesized and subsequently cured with m-phenylenediamine. Dielectric properties of the cured resin derived from the para isomer were measured between 25 and 100°C. The ambient temperature dielectric constant of the resin at 1 kc./sec. was 3.4, its dissipation factor was 0.01, and its volume resistivity was 1014 ohm-cm. at 500 v. d.c. Several allylphenylsiloxanes were also prepared by the cohydrolysis of allylphenyldimethylethoxysilane with dimethyldiethoxysilane, bis(dimethylethoxysilyl)benzene, and methyltriethoxysilane. Preliminary epoxidation studies on these latter materials were also carried out.
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  • 175
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2783-2789 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of isoprene with styrene initiated with sec-butyllithium in cyclohexane solution has been studied by kinetic methods. The rates of the homopolymerization have been measured by normal methods. The rates of the cross-propagation reactions were measured by the rate of appearance or disappearance of the ultraviolet absorption of polystyryllithium when the individual chain ends were reacted with the opposite monomer in the absence of the first. The rates of some of the reactions were also measured in the presence of the other monomer. It was found that polyisoprenyllithium reacted with both monomers with a one quarter-order dependence, and the polystyryllithium with a one half-order dependence. It was found possible to describe the copolymerization in terms of the four individual rate constants and to predict the initial copolymer composition. It was not found necessary to resort to explanations based on preferential absorption of isoprene around the chain ends to explain the high isoprene content of the copolymer.
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  • 176
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    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of methyl methacrylate can be initiated by a charge-transfer complex of liquid sulfur dioxide and pyridine in the presence of carbon tetrachloride. The molar ratio of sulfur dioxide and pyridine which participated in the complex was found from a spectrophotometric study to be 2:1. The polymerization proceeds through free-radical intermediates. The overall rate of polymerization is proportional to the square root of the concentration of the complex, and the values of kp/kt1/2 under the various polymerization conditions were satisfactorily consistent with the literature value. For the activation energy of the overall reaction, 8.2 kcal./mole was obtained, and for initiation, 9.7 kcal./mole was evaluated from the values of kp/kt1/2. It was deduced from a kinetic mechanism for the initiation that a primary radical may be produced from the reduction of carbon tetrachloride by an associated complex consisting of liquid sulfur dioxide-pyridine complex and the monomer.
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  • 177
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2815-2823 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The influence of SeOCl2 on the polymerization of propylene by TiCl3-Al(C2H5)3, and the temperature dependence of the stereospecificity of the catalyst, TiCl3-Al(C2H5)3, have been investigated. SeOCl2 decreases the rate of polymerization and increase the stereospecificity of the catalyst, which could be explained on the basis of a decrease of the concentration of Al(C2H5)3 accompanied by a reaction between Al(C2H5)3 and SeOCl2. On the other hand, the stereospecificity of the catalyst, TiCl3-Al(C2H5)3, increases gradually with a decrease in polymerization temperature from 40 to 0°C. From these results, we conclude that SeOCl2 exerts no essential influence on the polymerization of propylene by TiCl3-Al(C2H5)3, and that the stereospecificity of the catalyst is attributed mainly to the reducing ability of the organometallic compound.
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  • 178
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2939-2941 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 179
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2946-2948 
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    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 180
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2961-2963 
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    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 181
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2973-2974 
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    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 182
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2997-3007 
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    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the solution polymerization of tetraoxane catalyzed by BF3·O(C2H5)2, trioxane and methanol-insoluble polymer were produced. However, the amounts of these products depend on the nature of solvent used. A critical concentration of tetraoxane is observed for the formation of methanol-insoluble polymer; at less than this critical concentration of tetraoxane no methanol-insoluble polymer is obtained, but trioxane is preferentially produced. This critical concentration of tetraoxane is higher in a more polar solvent, so the amount of methanol-insoluble polymer produced decreases and the amount of trioxane produced increases with increasing the polarity of solvent used. These results may be explained in terms of a stabilization of the active center leading to formation of trioxane by a solvation with solvent.
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  • 183
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 3091-3101 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate constants for the autoxidation of polypropylene were determined by a combined ESR, volumetric, and chemical method. The values of ki, kp, and kt at 110°C. are 3 × 10-4 sec.-1, 1.9 l./mole-sec., and 3 × 106 l./mole-sec., respectively. The values of ki and its activation energy are the same as those for the decomposition of polypropylene hydroperoxide, thus identifying the latter as the principal initiation process. The values of the temperature-independent kt suggest that secondary peroxy radicals are the terminating species. The rate constants are compared with rate constant ratios for initiated autoxidations of squalane and other related systems.
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  • 184
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 3139-3150 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dialkylzinc-Lewis base systems are found to be active catalysts for the polymerization of alkylene oxides. The diethylzinc-dimethyl sulfoxide system is especially effective in the preparation of high polymers of ethylene oxide and propylene oxide. Diethylzine does not react with dimethyl sulfoxide, but there is strong association between the compounds. The proton magnetic resonance spectrum of a poly(ethylene oxide) prepared by the catalyst system suggests that the n-butoxyl group is attached to the end of the polymer chain. Polymerization of ethylene oxide seems to be initiated by the ethyl-zinc bond. The active species of the system seems to be diethylzinc coordinated with dimethyl sulfoxide. The efficiency of the catalyst system for the formation of high molecular weight polymer is 10-1-10-2. The other part of the catalyst is responsible for the formation of low polymers.
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  • 185
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 171-174 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Grignard reagent-initiated polymerization of thietane gave a soluble crystalline polymer melting at 59°C. Oxidation of the polymer with one or two equivalents of hydrogen peroxide gave the sulfoxide and sulfone, respectively. The sulfoxide was noncrystalline and insoluble in all common solvents at room temperature and softened at 185-200°C. The sulfone was partially crystalline and insoluble.
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  • 186
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 175-181 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ozonation followed by lithium aluminum hydride reduction cleaved high molecular weight isotactic poly(propylene oxide) to crystalline polyglycols. From the melting point and molecular weight of the latter, the molar freezing point depression produced by end groups is found to be ca. 18°C./mole, as compared to that estimated for poly(ethylene glycols), Kf = 12°C./mole, from earlier data. By assuming syndiotactic placements (or other irregularities) would produce the same molar depression, the melting point of isotactic poly(propylene oxides) produced by various catalysts has been used to estimate the isotactic sequence lengths.
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  • 187
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 183-192 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High molecular copolymers of trioxane with different cyclic ethers and formals were produced by γ-radiation from a 60Co source. It was polymerized in the solid state at 53°C. Polymerization does not occur in the melt. Irradiation was carried out with exclusion of air at a dose rate of 7 × 103 rad/hr. The polymerization rate was increased very considerably in the presence of 1,3-dioxolane and epichlorhydrin; the addition of other comonomers may reduce the yield. The concentration of the comonomer is generally higher in the polymer than in the initial mix. These comonomers which increase the polymerization rate are introduced preferentially into the polymer chain; this is proved by the unstable polymer part and the thermal stability. Experiments with the trioxane-1,3-dioxolane system revealed that the unstable polymer part is markedly reduced and the heat stability considerably inproved with rising concentrations of this monomer. The thermal stability and the reduced viscosity of these copolymers are within the range of technical processability.
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  • 188
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 215-226 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The influence of preparative conditions on the molecular weight and stereoregularity distributions of polypropylene was investigated. The stereoregularity distribution is narrowed by using a highly stereospecific catalyst, by decreasing the polymerization temperature, and for the three-component catalyst by keeping the mole proportion of the electron-donating third component at 0.5. The molecular weight distribution can be narrowed by using a highly stereospecific catalyst, a high monomer concentration, and a high polymerization temperature, and by having a lower conversion, particularly at low monomer concentration. The possibility of long-chain branching in polypropylene was indicated by data from the fractionation of tritium-labeled polymers.
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  • 189
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 237-238 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 190
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 265-272 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ESR spectra were studied for irradiated 3,3-bis(chloromethyl)oxetane (BCMO) single crystals and poly-BCMO obtained by polymerizing BCMO single crystals in solid state. In both cases, the spectra consist of the superposition of two-line and threeline components at -196°C. On warming the sample, only the former survived. From the examination of hyperfine coupling tensors, it is concluded that the two-line spectrum is due to the free radicals for the monomer and —C(CH2Cl)2—ĊH—O— for the polymer sample, respectively. The orientation of the free radicals gives information about the mode of ring opening in the solid-state polymerization of BCMO.
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  • 191
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 307-321 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The syntheses and polymerizations of (2-oxo-1,3-dioxolan-4-yl)methyl acrylate, 4-(2-oxo-1,3-dioxolan-4-yl)methyl itaconate, and (2-oxo-1,3-dioxolan-4-yl)methyl maleate are described. Reactivity ratios in the copolymerization of these monomers with other comonomers are reported and the Alfrey-Price Q and e values calculated. The post-polymerization effects of ultraviolet light and heat on these polymers and copolymers are presented and compared to those for similar polymers containing the 2,2-dimethyl-1,3-dixolane groups, which performs as an internal ultraviolet sensitizer. The 2-oxo derivatives are crosslinked thermally but not by ultraviolet light. The crosslinking reaction can be catalyzed by acids, bases, and salts.
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  • 192
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 365-379 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carboranes attached to silicon through straight-chain alkyl groups were prepared and characterized for thermal stability by TGA and molecular weight change on heating. The monomers for these polymers were prepared generally by platinum-catalyzed addition of a silylhydride to an alkenyl or dialkenyl carborane. Polymerization was effected by hydrolysis-condensation of chlorosilanes, ring opening of cyclosiloxanes, and condensation of alkoxy and chlorosilanes. Two types of polymer structures were prepared, one contained m-carborane in the chain backbone, the other contained o-carborane as pendant alkylcarborane groups. Both types were obtained as elastomers; however, higher proportions of carborane in the polymers reduced elasticity and finally resulted in nonelastomers. TGA of the backbone carborane siloxane polymer indicated degradation at 370°C. in nitrogen and at 235°C. in air. Chain scission, as determined by molecular weight decrease, was observed on heating in nitrogen at 350°C. TGA of the pendant carborane siloxane polymer indicated that degradation in nitrogen and in air occurred at greater than 400°C. However, chain scission, as determined by molecular weight decrease, was observed upon heating at 300°C. in nitrogen.
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  • 193
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    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The relative stabilities of symmetrically substituted polysiloxanes and polyoxymethylenes are compared in terms of the side-group steric overlap parameters, by means of a semiempirical method described previously. The results provide a qualitative estimate of the relative thermodynamic ease of polymerization of cyclic siloxanes or monomeric methylene oxides or, conversely, of the relative resistance to depolymerization of the polymers. These calculated values are compared with those reported previously for phosphazenes. In general, for polymers of the type, [R2Si—O]n, [R2C—O]n, and [R2P=N]n, if the side group, R, is small (H, halogen or methyl) the inherent steric and bonding characteristics of the chain should cause the polymer stabilities to decrease in the order phosphazenes ≈ siloxanes ≫ oxymethylenes. If, however, bulkier side groups are present, the order of decreasing stability to depolymerization should be siloxanes 〉 phosphazenes ≫ oxymethylenes. In all cases, the depolymerization tendency should increase markedly as the side group overlap parameters increase, and polyoxymethylenes should be the most sensitive to such changes. The calculated results are compared with the limited experimental evidence at present available.
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  • 194
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 407-416 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: By extensive ozonation and lithium aluminum hydride reduction, poly(propylene oxide) can be converted to material containing dipropylene glycol. Since the diprimary, disecondary, and primary-secondary isomers are readily separable by vapor-phase chromatography, it has been possible to show that some (but not all) noncrystalline PPO samples contain many head-to-head, tail-to-tail monomer units. Correlation of the fraction of head-to-head units with the optical rotation of noncrystalline fractions from optically active monomer, indicates that there is one asymmetric center inverted for every unit inserted head-to-head. The earlier suggestion that the noncrystalline fraction was due to atactic stereochemistry is thus shown to be generally incorrect in favor of an explanation due to positional isomerization.
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  • 195
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 439-454 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The graft copolymerizations onto the preirradiated polypropylene fibers of gaseous vinyl chloride and also of gaseous vinylidene chloride were carried out. The fibers were preirradiated with γ-rays from a 60Co source at -78°C. in air to a total dose of 8 X 105 rad, and were thus presumed to contain peroxide radicals which were active in grafting at ordinary temperature. The volume decrease of monomers at constant pressures due to the sorption and the grafting reaction was followed automatically at temperatures ranging from -10 to 80°C. The net monomer consumption through the grafting process was estimated by subtracting the volume change due to the sorption from the total volume change of monomers. In general, the extent of grafting was lower at the higher grafting temperature and the decrease of the grafting activity of fibers was also accelerated. The grafting was found to increase almost linearly with the logarithm of the reaction time and the logarithm of the radiation of the radiation dose to the fibers. The extent of grafting was also proportional to the vapor pressure of monomer at a given reaction temperature and was supposed to be controlled by the amount of the monomer adsorbed. Raising the irradiation temperature higher than 0°C. brought about a marked decrease in the activity of preirradiated polypropylene. The grafting activity was successfully retained by the polymer for at least a fortnight at -78°C.
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  • 196
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 503-509 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The γ-ray-initiated polymerization of butadiene, isoprene, and 2,3-dimethylbutadiene-1,3 was carried out at temperatures of 20°C. and -78°C. Polymers of butadiene and isoprene with mixed linear and cyclic structure were proved to result from the polymerization at -78°C. A monocyclic structure was found for the 2,3-dimethylbutadiene-1,3 polymers initiated either at -78°C. or in the thiourea canal complex at 20°C.
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  • 197
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 511-520 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Butadiene was polymerized by catalysts of the type: metal acetylacetonate (metal: Ti to Ni in the periodic table)-triethylaluminum-aluminum halide, with various ratios of triethylaluminum to aluminum halide. The minimum cis content was observed with vanadium catalyst in all cases, while the minimum polymer yields were observed with the iron and the manganese catalysts. These transition metal effects are discussed in terms of the crystal field theory, and it is suggested that the electrostatic interaction between the nearly nonbonding electrons of transition metal atom and a butadiene molecule or a growing end of the polymeric chain plays an important role in the stereoregular polymerization of butadiene by homogeneous Ziegler-Natta catalysts.
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  • 198
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 563-583 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aliphatic aldehydes have been condensed with cyanoacetic acid and the resulting olefin intermediates hydrogenated and then submitted to a Mannich-type reaction to produce α-alkylacrylonitriles with the alkyl groups ranging from C1 to C12. It was not necessary to isolate the intermediates when the reactions were carried out in acetonitrile solutions. The α-alkylacrylonitriles with C7 or higher alkyl groups in the chains would polymerize by radical initiation in emulsion to give polymers which were sticky, rubbery products and showed adhesive characteristics. Anionic initiation did not yield polymers with the α-alkylacrylonitriles containing high alkyl groups but did convert the C2 to C4 alkyl-substituted acrylonitriles to low molecular weight colored products. Some copolymers of α-alkylacrylonitriles with acrylonitrile were prepared in emulsion by radical initiation. The monomer ratios in these copolymers were determined by nuclear magnetic resonance spectra.
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  • 199
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 553-561 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aromatic polysulfonamides have been prepared by solution polycondensation of aromatic disulfonyl chlorides and aromatic diamines with a suitable acid acceptor in such solvents as N,N-dimethylacetamide and tetramethylenesulfone. The highest molecular weight polymers were obtained by using 2,6-dimethylpyridine as the acid acceptor in tetramethylenesulfone as the solvent. Clear, translucent, brittle films of the polysulfonamides may be formed from solution or from melt.
    Additional Material: 3 Tab.
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  • 200
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    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 537-543 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of three true polyampholytes with unequivocally alternating acidic and basic groups attached directly to the skeletal backbone of the polymer chain have been prepared. This was accomplished by copolymerizing 3,6-diallyl-2-piperidone with the α,ω-dithiols containing 2-, 4-, and 6-methylene groups. The polymerization was carried out in an emulsion system initiated by 2,2′-azobisisobutyronitrile (AIBN), yielding soluble piperidone-containing polymers with molecular weights in the 20,000-30,000 range. The piperidone rings in the polymers were hydrolyzed by dilute sulfuric acid to yield the desired polyampholytes. Fibers were prepared by wet-spinning formic acid solutions of the polyampholyte into saturated salt solution or by melt-spinning. These fibers were quite elastic. We were unsuccessful in demonstrating that mechanical energy could be attained by the effect of pH on the fibers. Similarly, no pH effect could be elicited in Instron tests. The stress-relaxation curve showed a marked positive force-temperature effect characteristic of rubberlike materials with few crosslinks. In a check of transition temperatures, it was noted that on repeated runs the second-order transition temperature rose markedly, suggesting an irreversible change. Viscometric studies clearly demonstrated polyelectrolyte behavior. X-ray diffraction studies of the polyampholytes showed that maximum crystallinity and orientation occurred in the polymer containing as part of the repeating unit the 1,4-butane dithiol moiety.
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