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  • 1960-1964  (6)
  • 1950-1954  (3)
  • Polymer and Materials Science  (9)
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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 7 (1963), S. 1015-1022 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The steady-state (d.c.) electrical conductivity of polypropylene has been measured as a function of temperature (25-150°C.) and field strength (0-94 kv./cm.). The temperature coefficient of the conductivity is 34.6 kcal./mole expressed as an activation energy. This is much larger than the activation energy for diffusion of small molecules in the same polymer. Thus, ionization rather than diffusion appears to be the primary activation process. The conductivity is nonohmic; the conductance quotient is a linear function of field strength but is larger than predicted by Onsager's theory. The ion “jump distance” as evaluated from the isothermal field dependence, is the same order of magnitude as the diffusional mean free path estimated from diffusion studies in other polymers. The conductivity, conduction activation energy, and field dependence appear to be relatively insensitive to polymer crystallinity.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 7 (1963), S. 783-787 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Monomers of vinyl formate, vinyl acetate, vinyl propionate, and vinyl butyrate were carefully purified by distillation in a Vigreux column and in a 56-plate glass helixpacked Todd column. The refractive indices and boiling points of the purified monomers agreed with those given in the literature. The purified samples were exposed to the radiation of a quartz mercury lamp in order to produce several per cent polymer. The refractive indices are tabulated and plotted in graphs.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 13 (1954), S. 263-277 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Assuming complete dissociation of the mineral acid in dilute aqueous solutions of a 1:1 vinyltoluene-styrene copolymer sulfonic acid and HCl, the degree of dissociation of the polyacid is apparently a constant independent of the concentration of either solute. On the basis of this result, it is likely that the polysulfonate chain initially contracts in such a manner with increasing HCl content of the solution that a maximum number of sulfonate groups remains on the surface of the coil. The variation of reduced viscosity (ηsp/c) with polyelectrolyte concentration c in the presence of a finite quantity of added “normal” electrolyte is determined mainly by the ratio of the counterions resulting from polyelectrolyte dissociation to the total counterion content of the solution. In regions of high dilution, where counterions from the polyelectrolyte are much less numerous than those from HCl, an apparently linear increase of reduced viscosity with increasing polymer concentration is observed. These data probably can be extrapolated to infinite dilution. Over the range of HCl concentrations 10-4 to 10-2 equivalent per liter the reciprocal square root of such extrapolated polysulfonic acid “limiting viscosity numbers” is proportional to the pH of the solvent. At the maxima of reduced viscosity plots the contribution of the polyelectrolyte to the hydrogen ion activity of the solution is half the contribution of the HCl: i.e., one third of the hydrogen ion activity is the result of polyelectrolyte dissociation. Moreover, the reduced viscosity at the maximum is directly proportional to the pH of the solvent. Curves of ηsp/c vs. c at high dilutions and constant pH are parabolas rather than straight lines. It is permissible to postulate rather convincingly from our data that the reduced viscosity curve of the polysulfonic acid in water possesses a maximum accurately indicated by the intercept of a Fuoss plot (cf. equation (7) in the text). The intercept of a Fuoss plot for any polyelectrolyte can have the significance of a limiting viscosity number only when measurements are made in a nonionizing solvent.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 14 (1954), S. 217-222 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 11 (1953), S. 447-454 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A simple and inexpensive instrument for measuring the osmotic pressure of polymer solutions has been designed. It consists of two 1-mm. I. D. Pyrex capillary tubes sealed into a flanged Pyrex sleeve, which is ground to fit snugly into a 19 × 60 mm. roundbased Alundum Thimble of medium porosity. A regenerated cellulose membrane is cast over the Alundum thimble, and the entire assembly is sealed in a test tube containing the polymer solution to be examined. This osmometer offers several unique advantages over others in current use. Its low cost and compact size permit inexpensive simultaneous measurement of many polymer solutions.A 1:3 copolymer of vinyltoluene and styrene monomers was separated into 24 cuts by fractional precipitation. On the basis of viscosity data these cuts were combined into 14 fractions. They were in the order of decreasing molecular weight, and infrared analysis indicated a uniform distribution of the ring methyl groups among the fractions. These two observations demonstrate that introduction of methyl groups into the benzene rings of a polystyrene molecule does not influence the polymer solubility appreciably.Osmotic molecular weights obtained with the Alundum thimble instruments and experimental limiting viscosity numbers gave values of 2.69 × 10-4 and 0.622 for K and α respectively in the Flory-Staudinger relation [η] = KMα. These results compare favorably with reported values for polystyrene samples prepared under similar conditions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 44 (1960), S. 271-272 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A general procedure is described by means of which the kp/kt1/2 ratio can be determined for the graft polymerization of vinyl monomers in an organic substrate. The method takes rigorous account of the influence of monomer diffusion on the reaction kinetics. As an experimental example, the mutual radiation grafting of styrene onto ethyl cellulose film by use of 2-M.e.v. Van de Graaff electrons to initiate free radical formation is described in detail.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The diffusion of styrene vapor in ethyl cellulose film has been studied as a function of styrene solubility in the film at 50°C. Methods and data are presented for determining the equilibrium solubility of styrene in ethyl cellulose as a function of vapor pressure at 50°C. The permeation rates of styrene vapor through 3-mil film were determined under steady state conditions for various pressures of pure styrene vapor on one side of the film and vacuum on the other side. From a plot of permeation rates versus styrene solubility the diffusion coefficient was calculated as a function of concentration. Measurements made over a concentration range of 0 to 0.7 g. styrene/cm.3 of unswollen film show that the diffusion coefficient first increases rapidly with concentration, then goes through a maximum, and finally levels off at 10-7 cm.2/sec. In the limited range of 0.06 to 0.10 g./cm.3 the diffusion coefficient varies exponentially with concentration as has been reported for other systems in a similar range. However, such a functionality does not represent the present system over a broad concentration range. These results, if generally applicable to other systems, indicate that the nature of the diffusion process for organic vapors in polymers may be considerably more complicated than formerly supposed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It was established that phenol-2,4-disulfonyl chloride and α-naphthol-2, 4-disulfonyl chloride introduce new intramolecular or tertiary bonds into lysozyme. The phenolic hydroxyl group seems to make the cross linking reagents soluble in aqueous media; it was established that a sulfonylating; species does dissolve prior to hydrolysis but that the chlorosulfonyl groups are hydrolyzed within seconds of dissolution. New covalently linked residues were shown to be introduced by different, spectra. Peptide maps of the lysozyme treated with phenol-2,4-disulfonyl chloride. peroxidized, and digested with trypsin showed definite deletions and additions when compared with the control. Partial analysis of the peptides showed that cross linking between ε-amino groups of lysine residues had occurred. A certain degree of stabilization of lysozyme to inactivation by certain inactivating conditions was noted after treatment with the two reagents. Ultra-centrifugal analysis of the lysozyme treated with phenol-2,4-disulfonyl chloride showed that there was no detectable fraction having a higher molecular weight than native lysozyme. Tentative assignments of positions of cross linking were made.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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