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  • Polymer and Materials Science  (117)
  • 2000-2004
  • 1965-1969  (117)
  • 1965  (117)
  • 1
    Electronic Resource
    Electronic Resource
    Kinetics of polymerization of styrene initiated by substituted benzoyl peroxides. III. Induced decomposition (1965)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 3 (1965), S. 1567-1571 
    Details
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The polymerization of styrene has been initiated by redox systems consisting of diethylaniline and symmetrically substituted benzoyl peroxides. Decomposition rate constants and efficiencies of initiation were determined by the dead-end technique. Hammett plots of these rate constants and of those previously determined for polystyryl-radical induced decomposition of substituted benzoyl peroxides have the same slope, suggesting that an SH2 mechanism is involved in the radical attack on peroxides just as in the radical attack on disulfides. The predictive ability of a combined Hammett-type equation was shown to be excellent for the decomposition rate constants of initiating systems consisting of both substituted diethylaniline and substituted benzoyl peroxide. The effect of substituents on the efficiency of initiation remains unexplained.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1965.100030424
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  • 2
    Electronic Resource
    Electronic Resource
    Physical properties of periodate-oxidized amylose: Aggregation of oxidized amylose in aqueous solutions (1965)
    New York : Wiley-Blackwell
    Biopolymers 3 (1965), S. 497-508 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ability of periodate-oxidized amylose to form aggregates in aqueous solution was studied by sedimentation, light scattering, and viscosity analyses. Ultracentrifuge schlieren patterns show that aggregation can be appreciable at pH 3.0 and 1.0. The hydroxyl ion-catalyzed degradation of the oxidized amylose is faster at pH 3.0 than at pH 1.0. Viscosity and sedimentation analyses conducted at pH 3.0 show that a minimum in the degree of aggregation of the oxidized molecules is obtained at 15-25% oxidation. Solubulity studies and x-ray diffraction patterns on retrograded amylose show that maximum solubility of the retrograded amylose is obtained by oxidizing to the extent of 25-35%. It was therefore concluded that in the general range of 20-30% periodate oxidation, the oxidized amylose has a minimum ability to form intermolecular hydrogen bonds. Outside of this range, oxidized amylose readily forms aggregates in aqueous solutions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1965.360030411
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  • 3
    Electronic Resource
    Electronic Resource
    Influence of counterion radius on the polyelectrolyte behavior of synthetic polypeptide solutions (1965)
    New York : Wiley-Blackwell
    Biopolymers 3 (1965), S. 545-554 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The influence of counterion radius on the polyelectrolyte behavior of poly-L-cysteate in aqueous solution under different conditions was investigated. A linear relationship was found between a critical concentration in solution of the synthetic charged poly-peptide and the crystallographic radius of different counterions, indicating that the stability of this macromolecule is inversely proportional to the size of the cations.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1965.360030505
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  • 4
    Electronic Resource
    Electronic Resource
    Interaction of aminoacridines with deoxyribonucleic acid: Effects of ionic strength, denaturation, and structure (1965)
    New York : Wiley-Blackwell
    Biopolymers 3 (1965), S. 135-153 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The binding curves of various aminoacridines on calf thymus DNA have been determined by a spectrophotometric method. The dominant role of electrostatic forces in the interaction has been confirmed by the effect of ionic strength. Side chain and ring substituents in the aminoacridines do not inhibit binding, since this decreases in the order: acranil 〉 neomonacrin 〉 atebrin 〉 9-aminoacridine ∼ proflavine 〉 9-amino-1,2,3,4-tetrahydroacridine (THA). The last named shows the effect of diminishing the flat area of the rings in the aminoacridines. The shape of the binding curves of proflavine, 9-aminoacridine, and THA on thermally denatured DNA show that about 30-50% more binding sites are available to these cations on denatured DNA than on native DNA, but that the binding constants are the same. These observations are discussed in relation to the intercalation and other models for the interaction. It is concluded that exact and complete intercalation is not a necessary condition of strong binding and that other, less regular, models, in which the positive ring nitrogens of the acridines are close to the DNA phosphates and the acridine rings partially interact with the DNA base rings, are probably more consistent with the effect of denaturation of DNA on the binding curves which are characteristic of the interaction in solution.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360030204
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  • 5
    Electronic Resource
    Electronic Resource
    Studies of the conformation of carboxymethyl amylose in aqueous solutionsThis work was supported by a grant from the Corn Industries Research Foundation. (1965)
    New York : Wiley-Blackwell
    Biopolymers 3 (1965), S. 185-193 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In an attempt to clarify certain questions of the configuration of amylose in aqueous solution, carboxymethyl groups were introduced into corn amylose (degree of substitution ca. 0.8) and certain properties of the derivative (CMA) studied. The intrinsic viscosity exhibits a strong increase between pH 2 and 6 but remains constant at higher pH. A pH 6 and above, CMA exhibits typical polyelectrolyte behavior. CMA does not form a complex with iodine at pH 6 or above but does form a violet-colored complex at low pH. The absorption maximum of the CMA complex lies at a somewhat lower wavelength (550 mμ) than that of the complex formed by the parent amylose. The reduced viscosity and specific optical rotation of the CMA-iodine complex remains constant up to a concentration of 1.2 mg. iodine/100 mg. CMA, then both properties decrease with further increases of iodine content. All of the above results and hydrogen ion titration behavior are in agreement with the hypothesis that CMA exists as a coil of short helical segments in acid solution and that these helical segments break down on ionization of the carboxyl groups. The specific optical rotation of CMA increases between pH 2 and 6, remains constant between pH 6 and 12, and decreases above pH 12. This later result shows that the similar decrease in rotation seen in amylose cannot be attributed, at least entirely, to a helix-coil transition. There must be another effect on optical rotation, direct or indirect, of the ionization of hydroxyl groups.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360030206
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  • 6
    Electronic Resource
    Electronic Resource
    Endgroup modification of unsaturated polyesters. Effect on chemical resistance (1965)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 1681-1700 
    Details
    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: Endgroups of unsaturated polyesters formulated with mole ratios of 2/1/3 and 1/1/2 isophthalic acid/maleic anhydride/propylene glycol were modified. Carboxylic acid content was effectively reduced by esterification with alcohols or epoxides, amidation with phenyl isocyanate, or neutralization with amines. Hydroxyl content was reduced by esterification with acids or anhydrides and urethane formation with phenyl isocyanate. Chemical resistance was determined by measuring the decrease in flexural strength and modulus with exposure to 10% solutions of sodium hydroxide and sulfuric acid at 82°C. A 2-week test using the medium chemical-resistant 2/1/3 polyester indicated that any modification which decreased the carboxylic acid content improved chemical resistance. Modifications which increased or decreased the hydroxyl content had no significant effect in the 2-week tests; however, decrease of hydroxyl content appeared important in 6-month exposure tests. The 1/1/2 resins which have high initial chemical resistance had poorer chemical resistance after endgroup modification than the unmodified 1/1/2 resin, with the exception of the phenyl isocyanate-modified product which was equal to the unmodified resin. Water (0.8%) and xylene (0.1%) had no effect on chemical resistance. However, larger amounts of residual solvent were disadvantageous.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1965.070090507
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  • 7
    Electronic Resource
    Electronic Resource
    Heptane-soluble material from atactic polypropylene. I. Fractionation and characterization of fractions (1965)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 2019-2029 
    Details
    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: A sample of commercial atactic polypropylene was extracted with ether and the residue extracted with boiling n-heptane. Six fractions of the heptane-soluble material, which is very similar to that obtained by heptane extraction of isotactic polypropylene, were obtained by stepwise addition of acetone to a solution in cyclohexane. Densities, melting points, and x-ray photographs of the fractions and the unfractionated material were obtained and infrared absorption spectra used to estimate tacticity. Molecular weights, determined by means of a vapor pressure osmometer, ranged from about 3000 to about 25,000. That of the fraction of highest molecular weight was in good agreement with a separate determination by means of osmotic pressure measurements. Separation in fractionation occurred in order of decreasing molecular weight and increasing crystallinity as estimated from densities and x-ray photographs. Tacticity also seems to increase with decreasing molecular weight. Melting points of the fractions were not entirely in the order expected from their molecular weights and estimated crystallinities, and it is possible that low DP isotactic material may be preferentially concentrated in the highest molecular weight fraction. It is emphasized that the unfractionated material may contain polymers possessing a range of order intermediate between those of purely atactic and purely isotactic polymer and that refractionation may be required in order to characterize the material completely.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1965.070090603
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  • 8
    Electronic Resource
    Electronic Resource
    Photodegradation of cis-1,4-polyisoprene sensitized by the addition of chloronitroso compounds (1965)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 2121-2130 
    Details
    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: It was found that chloronitroso compounds with a free non-conjugated nitroso group show a considerable sensitizing activity in respect to the process of photochemical degradation of dissolved cis-1,4-polyisoprene, which is induced by visible radiation (4000-7000 A.). The effect of 10 chloronitroso sensitizing compounds were investigated. The highest sensitizing activity was found with compounds 2,2-chloronitrosopropane and 1,1-chloronitrosocyclohexane. The maximum wavelength, of which the decrease of relative viscosity of solutions was the highest, was determined for 2,2-chloronitrosopropane. The highest sensitizing activity of chloronitroso compounds was found for wavelengths corresponding to the absorption maximum of the sensitizer added. The theory of the sensitizing activity of chloronitroso compounds is proposed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1965.070090609
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  • 9
    Electronic Resource
    Electronic Resource
    Characterization of block and random ethylene-propylene copolymers by differential thermal analysisPresented in part before the Division of Polymer Chemistry, 148th National Meeting of the American Chemical Society, Chicago, August 30-September 4, 1964. (1965)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 3061-3069 
    Details
    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: A group of C14-tagged ethylene and propylene polymers consisting of physical mixtures of homopolymers, block copolymers made up of two homopolymer sequences, and block copolymers made up of several homopolymer segments has been studied by differential thermal analysis (DTA). The effect of randomness in copolymers has also been studied in this set of systems, which contains 0-51 wt.-% ethylene. Block copolymers and physical mixtures have been found to have thermograms with endothermal minima at approximately 138 and 163°C. The ratio of heights of the two minima has been found to be a function of the ethylene and propylene content for mixtures of homopolymers and for block copolymers without randomness. DTA thus provides an analysis for monomer ratios in physical mixtures and in block copolymers of ethylene and propylene. The cooling thermograms of block copolymers have been demonstrated to have two exotherms in all cases where the block ethylene content exceeded 10%; the propylene limit was not fixed. Mixed homopolymers do not exhibit two freezing exotherms. The total heat of fusion of the polymer has been found to be a usable measure of chain randomness and block nature. The conditions for observation of single and multiple transitions have been extended.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1965.070090912
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  • 10
    Electronic Resource
    Electronic Resource
    Glyceryl methacrylate hydrogels (1965)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 3161-3170 
    Details
    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: Hydrophilic three-dimensional polymer networks (hydrogels) were prepared from glyceryl methacrylate (2,3-dihydroxypropyl methacrylate). The solubility of poly(glyceryl methacrylate) in water permits the preparation of transparent hydrogels containing variable amounts of water at the equilibrium stage. This is accomplished by varying the degree of swelling at the time of network formation, and by varying the density of crosslinks. The temperature dependence of swelling of the hydrogels in water and in 0.9% sodium chloride solution, was determined. There exists a linear relationship between the refractive index and the per cent of water in the hydrogel. These hydrogels are potentially useful in ophthalmology.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1965.070090920
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