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  • Polymer and Materials Science  (11)
  • Humans
  • 1965-1969  (11)
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 1681-1700 
    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.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 799-800 
    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
    Additional Material: 1 Tab.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 10 (1966), S. 1809-1812 
    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: Dianhydrides from ethylbenzene, cumene, and branched C5-C6 alkylbenzene-maleic anhydride photoadducts have a surprisingly high solubility in epoxy resins. Dianhydrides from benzene, toluene, and n-C10-C13 alkylbenzene adducts, which are homologs of the above, were not soluble. Epoxies cured with the ethylbenzene and cumene dianhydride adducts had higher heat distortion temperatures and flexural strengths than epoxies cured with two commerical monoanhydrides. High-melting polyimides were also obtained with these two new dianhydrides.
    Additional Material: 1 Tab.
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 4 (1966), S. 2179-2200 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: p-Chlorophenyldiazonium hexafluorophosphate is shown to be a convenient and effective catalyst for initiating the polymerization of tetrahydrofuran (TH) and other cyclic ethers. The polymerizations apparently proceed without any significant termination or transfer reactions (i.e., “living” polymers result), and materials of very high molecular weight can be obtained. A mobile monomer-polymer equilibrium for THF was obtained during polymerization and equilibrium conversions were determined at a number of temperatures. The ceiling temperature derived from these data was 84°C., the heat of polymerization was -4.58 kcal./mole and the corresponding entropy change was - 17.7 cal./°C.-mole. Hydrocarbons are suitable inert solvents for these polymerizations, but concentrated solutions must be used at ambient temperatures in order to stay above the required equilibrium monomer conceiitration and also to dissolve the catalyst which is insoluble in hydrocarbons. It was shown that acyclic ethers act as transfer agents in these polymerizations and that transfer with consequent reduction of molecular weight continues even after monomer-polymer equilibrium is reached. Cyclic ethers do not act as transfer agents but only copolymerize. Trimethyl orthoformate was shown to be a particularly effective transfer agent; it resulted in a polymer with methoxy endgroups and produced methyl formate as a by-product. The data obtained are consistent with a mechanism involving initiation by hydrogen abstraction and polymerization via tertiary oxonium ions associated with PF-6 gegenions. This gegenion is thought to be responsible for the “living” nature of the system.
    Additional Material: 5 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 2641-2649 
    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: Several samples of polyethylene were exposed to attack by fuming nitric acid and the resulting changes in density, infrared absorption, and visual appearance were recorded. The motivation for this investigation lies in the possibility of using acid etching as a means of studying the structure of interspherulitic regions in polyethylene and the relations between these and structure-sensitive properties such as stress-crack resistance. The results indicate that certain parts of the samples were attacked preferentially by the acid; the residual material, though of a porous gross structure, was of higher density than that of the average initial material. The differences in visual appearance were the most dramatic and appear to correlate with stress-crack resistance. Insofar as quantitative characterization of interspherulitic regions are concerned, the merits of this method of investigation are still in doubt and await further study.
    Additional Material: 5 Ill.
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  • 6
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Eine Reihe Amyloseester aus dem Bereich vom Acetat bis zum Caproat wurden hergestellt. Für jede Substanz wurden der Schmelzpunkt und die Glasübergangstemperatur gemessen. Es wurde beobachtet, daß beide Temperaturen durch Verlängerung der Esterseitenkette erniedrigt werden. Auf Grund der Annahme, daß dies auf einem inneren Plastifizierungsvorgang beruht, kommt man auf Abschätzungen von Tm ≃ 800°K und Tg ≃ 590°K Für unsubstituierte Amylose. Der Durchschnittswert von Tg/Tm wurde auf ungefähr 0.80 berechnet, was auf eine ziemlich steife und unsymmetrische Polymerstruktur schließen läßt.
    Notes: Various amylose esters ranging from the acetate to the caproate were prepared. Melting and glass transition temperatures were measured for each and it was observed that both Tm and Tg were depressed as the chain length of the substituted ester side chain was increased. By assuming this to be an internal plasticization process, estimates of Tm ≃ 800°K and Tg ≃ 590°K were obtained for the unsubstituted amylose molecule. An average value of (Tg/Tm) of 0.80 was calculated for these esters which would suggest that they are moderately rigid, unsymmetrical polymers.
    Additional Material: 1 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 3 (1965), S. 4000-4000 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 7 (1969), S. 945-957 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two high molecular weight (ηinh 〉 1.0) soluble poly-as-triazines have been prepared by the solution polycondensation in m-cresol of 2,6-pyridinediyl dihydrazidine with p,p′-oxybis(phenyleneglyoxal hydrate) and with p,p′-oxydibenzil. Thermal characterization of the poly-as-triazines by TGA showed polymer decomposition temperatures of ∼400°C after a 300°C cure in argon. Poly-as-triazines exhibited weight losses 〈8% after aging in static air at 316°C for 200 hr. Clear yellow films cast for m-cresol solutions exhibited good flexibility and toughness even after aging at 316°C for 200 hr in air and after refluxing in 10% aqueous potassium hydroxide solution for 24 hr.
    Additional Material: 5 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 3 (1965), S. 1785-1792 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The storage and loss shear compliances (J′, J″) of poly(n-butyl methacrylate) (number-average molecular weight 320,000) were measured at frequencies between 0.08 and 1.0 cycle/sec. in the temperature range of 18-33°C., encompassing the glass transition. Data were obtained both at voluminal equilibrium and as a function of time during the slow isothermal contraction which follows a quench to a temperature near the transition. The latter data were supplemented by dilatometric measurements on similar samples to determine the magnitude of the volume contraction. Correlation of the dependences of J′ and J″ on temperature and on elapsed time (at constant frequency) indicated that the relaxation mechanisms are controlled primarily by free volume. The method of reduced variables was successfully applied to the dependence of J′ on temperature and elapsed time using shift factors aT,t calculated from the modified Doolittle equation and the magnitudes of volume contraction measured dilatometrically. The dependence of J″ on both temperature and elapsed time was more complicated, indicating a change in the shape of the retardation spectrum with free volume. The behavior is qualitatively very similar to that of poly(vinyl acetate), previously studied, except that the magnitudes of J′ are considerably larger and the thermal expansion coefficient of the free volume is smaller.
    Additional Material: 6 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 3 (1965), S. 2033-2045 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Experimental techniques for observing total and spectral thermochemiluminescence (TCL) are discussed in general along with some data for the systems polycarbonate-O2, polycarbonate-CO, and polypropylene-O2. Since TCL is the process whereby heated materials undergo thermally activated reactions and emit light in excess of the amount prescribed by the blackbody radiation law, its study may be expected to yield information about the structure and degradation of the materials. It has been observed that TCL spectra are both time- and temperature-dependent. A simple mathematical model for analyzing TCL data under conditions of a linear heating rate is discussed. The result also should be of use in thermogravimetric analysis.
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