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  • 1
    Electronic Resource
    Electronic Resource
    Thermal degradation of polymers. I. Aspects of polytetrafluoroethylene degradation (1962)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 58 (1962), S. 1283-1291 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The mechanism of the thermal degradation of polytetrafluoroethylene is investigated. It is shown that the chain transfer reaction should not be ignored and that a reasonable explanation for the observation that monomer is almost the exclusive product of vacuum thermal degradation is the rate of diffusion and volatilization of larger fragments from the polymer. Diffusion of tetrafluoroethylene and hexafluoropropylene through polytetrafluoroethylene was studied. The diffusivities are 72 and 39 × 10-10 cm.2/sec. for C2F4 and C3F6, respectively, at 24°C. An apparatus for measuring the weight and temperature of degrading polymers under vacuum is also described.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1962.1205816683
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  • 2
    Electronic Resource
    Electronic Resource
    Thermal degradation of polybis(p-isopropylphenoxy)-phosphazene (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 1505-1515 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polybis(p-isopropylphenoxy)phosphazene was treated thermally at 100, 135, 200, and 300°C. The resulting reductions in weight-average molecular weights were monitored by gel-permeation chromatography, and the experimental observations led to the adoption of a random chain-scission model. An effective energy of activation and entropy of activation were calculated for the degradation process, and these values were found to be consistent with a random-scission model. The analysis was, in part, based on a computer-simulated first-order degradation model. This polymer showed higher thermal stability than previously reported polyaryloxyphosphazenes.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160705
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  • 3
    Electronic Resource
    Electronic Resource
    The synthesis and thermal curing parameters of a novel quinoxaline monomer with terminal ethynyl thermoset and phenylethynyl intramolecular cycloaddition postcure capability (1982)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 20 (1982), S. 3069-3078 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Synthesis of 3,3′-bis(4-[3-ethynylphenoxy]phenyl)-7,7′-bis(phenylethynyl)-2,2′-diphenyl-6,6′-biquinoxaline (I) was accomplished by the reaction of 2,2′-bis(phenylethynyl)-5,5′-diaminobenzidine (II) and 4-(3-ethynylphenoxy)benzil. Thermal analysis of I indicated a softening temperature of 107°C, followed by an exotherm above 150°C that corresponded to a independent crosslinking reaction of the terminal acetylene groups and an intramolecular cycloaddition (IMC) reaction of the 2,2′-bis(phenylethynyl)biphenyl moieties. In the synthetic work substantial improvements were made in the synthesis of II. The sample of I was cured at 200°C and the maximum partially cured transition temperature attained was 280°C. A sample of 3,3′-bis(4,[3-ethynylphenoxy]phenyl)-2,2′-diphenyl-6,6′-biquinoxaline (IV) was similarly tested as a model without IMC capability and its corresponding value was 250°C. The difference between these two values is discussed briefly.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1982.170201103
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesis and characterization of polyaryloxyphosphazene copolymers (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 361-369 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of polyaryloxyphosphazene copolymers with the general formulas [NP(OC6H5)(OR)]n and [NP(OC6H4-4-OCH3)(OR)]n, where R = C6H4-4-CH3, C6H4-4-C2H5, C6H4-4-isoC3H7, C6H4-4-sec-C4H9, C6H4-4-tert-C4H9, C6H4-4-OCH3 or C6H4-4-OC4H9, have been prepared under anhydrous conditions. Copolymers as well as selected homopolymers were prepared by the reaction of polydichlorophosphazene with appropriate sodium aryloxides. Each of the polymers was characterized by elemental analysis, infrared spectroscopy, gel-permeation chromatography, and differential scanning calorimetry. Elemental analysis established the empirical formula for the polymers and showed that there were no residual P—Cl bonds left on the polymer backbone. Infrared spectroscopy indicated the presence of a phosphorus-nitrogen backbone with two aryloxy groups bonded to each phosphorus atom. The copolymers examined exhibited molecular weights of above 1 × 106. Polyaryloxyphosphazene copolymers were examined by differential scanning calorimetry and compared to several of the corresponding homopolymers. Glass transition temperatures ranged between -34 and +44°C for the polymers. The Kelley-Bueche equation was used to predict the glass transition temperatures of the copolymers. Close agreement was found between calculated and experimental values for most of the systems examined.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.170150210
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  • 5
    Electronic Resource
    Electronic Resource
    Characterization of acetylene terminated sulfone (ATS) resin. I. Chemical characterization of the resin (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 665-677 
    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: An acetylene terminated sulfone resin mixture, prepared under contract for the Air Force, was subjected to a fairly extensive compositional analysis. Monomer, dimer, higher oligomers, solvents, and anomalous side products of synthesis were isolated, identified, and quantified using separatory procedures such as column chromatography and thin film flash distillation, in conjunction with techniques of chemical analysis such as infrared and nuclear magnetic resonance spectroscopy, size exclusion chromatography, and elemental analysis. By these means we were able to precisely characterize the resin mixture and, by so doing, identify some side products of synthesis; most notably, a class of abnormal coupling product able to chelato palladium (a catalyst used in acetylation of the resin) and, therefore, accelerate subsequent acetylene polymerizations in the resin mixture.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070420312
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  • 6
    Electronic Resource
    Electronic Resource
    Characterization of acetylene terminated sulfone (ATS) resin. II. Thermal analysis of the resin (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 679-691 
    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: The kinetics and thermodynamics of the cure and post-cure reactions of an acetylene terminated sulfone (ATS) resin mixture and pure fractions from that mixture were studied using differential scanning calorimetry. Thermal stabilities were measured by programmed thermogravimetry under helium, and oxidative stabilities using isothermal thermogravimetry in air. Microstructural changes accompanying the cure reaction were identified using infrared spectroscopy. Early products of thermal degradation were trapped for identification and quantitative analysis using the technique of sub-ambient thermal volatilization analysis. We found that glass transition temperatures increase with crosslink density in the resin, that oxygen is able to copolymerize or couple with the polyenes to produce peroxides or hydroperoxides (respectively) which subsequently decompose to form terminal alcohols on the polyene, that weight loss in air at 600°F is an oxidative process that is insensitive to resin crosslink density, and that sulfone functionality constitutes the thermal weak link in the ATS resin system.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070420313
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  • 7
    Electronic Resource
    Electronic Resource
    Annealing of plasticized PVC. Dilatometric and DSC observations (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 1395-1400 
    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: Isothermal dilatometric measurements on quenched, plasticized PVC have been made at a series of temperatures, and a mathematical expression has been obtained to described the specific volume as a function of time. The results of these measurements, along with those obtained using differential scanning colorimetry (DSC) for the change in enthalpy accompanying annealing, clearly show a change in the character of the annealing process with rising temperature; but the underlying molecular kinetic mechanism apparently remains unchanged.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1977.070210521
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  • 8
    Electronic Resource
    Electronic Resource
    Aqueous solutions of polyvinylpyrrolidone (1968)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 116 (1968), S. 96-106 
    Details
    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: Das Verhalten von Polyvinylpyrrolidon in Wasser und in Salzlösungen wurde durch Messungen der Wärmekapazitäten, der spezifischen Volumina und der reduzierten Viskositäten untersucht. Die Lösungswärmen von PVP in Wasser liegen bei ungefähr -4 kcal/mol Monomereneinheit, während sie im Falle der Salzlösungen niedriger sind. Die Resultate werden im Lichte des Mechanismus für den Stabilisierungseffekt. den hydrophile Kolloide auf hydrophobe ausüben, diskutiert. Es wurde kein Hinwels für die Existenz von „strukturiertem Wasser“ in der Nähe der Polymeren gefunden; somit scheint es nicht möglich zu sein, die Stabilisierung des Kolloids durch Hydrathüllen von „eisähnlichem Wasser“ zu erklären. Es wird ein Stabilisierungsmechanismus vorgeschlagen, der auf einer Erhöhung der Mischungswärmen des Kolloids in Wasser beruht.
    Notes: The properties of polyvinylpyrrolidone, in water and salt solutions, are examined by measuring the heat capacities, specific volumes and reduced viscosities. The heats of solution in water are of the order of -4 kcal per mole of monomer unit, they are decreased in the presence of salts. The results are discussed in terms of the mechanism of the stabilizing effect of hydrophylic colloids on hydrophobic ones. No evidence is found in terms of the existence of more “structural water” in the vicinities of the polymer molecules; this is taken to imply that stabilization is not effected through hydration multilayers of “ice-like water”. A mechanism of stabilization based on the signs and magnitudes of the heats of solution of colloids in water is proposed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1968.021160109
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  • 9
    Electronic Resource
    Electronic Resource
    Heterogeneous nucleation and growth of spherulites from a polycaprolactone (poly(1-oxy-6-oxohexamethylene)) melt (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 2483-2488 
    Details
    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: Es wird über den Beginn einer Untersuchung zur Kristallisationskinetik von Polycaprolacton (Poly(1-oxy-6-oxohexamethylene) (1)) berichtet. Die primäre Keimbildung und das primäre Sphärolith-Wachstum aus der Polymerschmelze werden bei hinreichend hohen Temperaturen verfolgt, wodurch sichergestellt ist, daß das Wachstum der Kristallite durch Keimbildung bestimmt ist. Die kinetischen Daten werden weitgehend mit Hilfe des Avrami-Modells interpretiert, welches sich gut auf die Kristallisation von 1 anwenden ließ.
    Notes: A kinetic crystallization study of polycaprolactone (poly(1-oxy-6-oxohexamethylene) (1)) has been initiated to investigate the primary nucleation and primary spherulitic growth from a polymer melt at temperatures that are high enough to insure nucleation-limited crystallite growth. The analysis of the kinetic data is largely made on the basis of an Avrami model which proved to be well suited for the interpretation of the crystallization of 1.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750821
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  • 10
    Electronic Resource
    Electronic Resource
    Predicting glass transition temperatures of linear polymers, random copolymers, and cured reactive oligomers from chemical structure (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1165-1176 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A reliable semiempirical method for predicting glass transition tempertures of linear polymers, random copolymers, and selected crosslinked networks from knowledge of only their chemical structure is presented. For cases in which new moieties not in the database are encountered, a scaling technique of similar moiety contributions has proven successful. The basic database was composed of 178 linear homopolymers ranging from aliphatic to aromatic heterocyclic polymers and 12 random copolymers. The crosslinked networks investigated in this study involved only diacetylene end-group reactions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230608
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