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  • 1
    Electronic Resource
    Electronic Resource
    Investigations of thermal elimination reactions of polymers by thermal volatilization analysis and ultraviolet spectroscopy (1969)
    Springer
    Journal of thermal analysis and calorimetry 1 (1969), S. 389-402 
    Details
    ISSN: 1572-8943
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Résumé L'emploi de la méthode d'analyse par volatilisation thermique avec condensation différentielle des produits volatils, sur des échantillons en film sur tubes de réaction en verresilice à fond plat permet l'examen des spectres ultraviolets des polymères partiellement dégradés et l'étude de la stabilité thermique, outre l'identification des constituants volatils. On a comparé le développement de la conjugaison dans le résidu non-volatil pour les polychlorure de vinyle, polychloroprène, polyacétate de vinyle et les copolymères acétate de vinyle/éthylène, polyformiate de vinyle et polyalcool vinylique. Dans chaque cas, on a observé une réaction d'élimination du groupe latéral à basse température et rupture du polyène entre 400 et 500°. Les plus longues séquences ont été formées dans le cas du PCV. Tous les polymères, excepté le PCV, montrent une certaine complexité de produits dans la réaction d'élimination.
    Abstract: Zusammenfassung Die Anwendung der thermischen Verdampfungsanalyse durch Differentialkondensation der flüchtigen Produkte an Filmproben in flachen Quarzglasreaktionsrohren gestattet die Ermittlung der UV-Spektren von teilweise degradierten Polymeren sowie Aussagen über die thermische Stabilität und Types des flüchtigen Produktes. Die Bindungen in dem nichtflüchtigen Rest wurden untersucht und im Falle der Copolymere Poly(vinylchlorid), Polychloropren, Poly(vinylacetat) und Vinylacetat/Äthylen, weiterhin Poly/vinylformat und Poly/vinylalkohol verglichen. Alle erleiden eine Eliminierungsreaktion an der Seitengruppe bei niedrigeren Temperaturen und Polyenabspaltung zwischen 400 und 500°. Die längsten Polyensequenzen werden durch PVC gebildet. Abgesehen vom PVC zeigten alle übrigen Polymere eine gewisse Komplexität in der Eliminierungsreaktion.
    Notes: Abstract Using thermal volatilization analysis with differential condensation of volatile products, with film samples on flat-bottomed silica glass reaction tubes to permit measurements of UV spectra of partly degraded polymer, the thermal stability, the types of volatile products and the development of conjugation in the involatile residue have been compared for poly(vinyl chloride), polychloroprene, poly(vinyl acetate) and vinyl acetate/ethylene copolymers, poly(vinyl formate) and poly(vinyl alcohol). All undergo a side-group elimination reaction at lower temperatures, and polyene breakdown occurs in all the samples between 400 and 500°. The longest polyene sequences are formed by PVC. All the polymers except PVC show some complexity of products in the elimination reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01983081
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  • 2
    Electronic Resource
    Electronic Resource
    Copolymerization of methacrylic acid esters with methacrylonitrile (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 36 (1959), S. 173-182 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The reactivity ratios in the copolymerization of methacrylonitrile with styrene, methacrylic acid, and eleven alkyl methacrylates have been determined and the Alfrey-Price Q and e values calculated. Monomer reactivity in these systems is principally a function of resonance stabilization (Q), polar factors (e) playing a relatively minor role. With the exception of the stearyl ester, the changes in the Q and e values which occur on ascending the homologous series can be accounted for qualitatively in terms of the expected relative electronic displacements and of the steric effects caused by the various alkyl groups. Some correlation between monomer reactivity and the depolymerizability of the corresponding polymer has been noted.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1203613014
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  • 3
    Electronic Resource
    Electronic Resource
    Thermal degradation of polymethacrylonitrile. Part V. The mechanism of the initiation step in coloration reactions (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 39 (1959), S. 211-222 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The coloration reaction of polymethacrylonitrile, which involves linking up of adjacent nitrile units, has previously been shown to be initiated by traces of methacrylic acid present in the polymer chains. It also occurs when pure polymer is heated with small quantities of a wide variety of substances including carboxylic acids, phenols, imides, and aliphatic amines. The carboxylic acid initiated reaction exhibits first order kinetics. The rates of initiation by a number of aromatic acids have been measured and compared with the pKa values. The initiating power is strongly influenced by the nature of substituents in the acid molecule, weaker acids giving a higher rate of initiation. A semiquantitative treatment has been applied to phenols with similar results. A mechanism for the initiation step in the color reaction is presented involving nucleophilic attack on a nitrile group. This is consistent with the results obtained for acids and phenols, and the observations of other workers on the alkali-induced coloration in solution are explained similarly. It is noted that all the substances capable of acting as initiators are Lewis bases.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1203913517
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  • 4
    Electronic Resource
    Electronic Resource
    Degradation of polymer mixtures. VIII. Blends of poly(vinyl acetate) with poly(methyl methacrylate) (1976)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 14 (1976), S. 1839-1856 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The degradation of blends of PVA and PMMA in the form of films cast from a common solution of the polymers has been studied by TVA, TG, and EGA (evolved gas analysis) for acetic acid. Volatile degradation products have been characterized by spectroscopic and GLC techniques. Molecular weight, spectral and thermal stability changes in PMMA extracted from partially degraded blends have been examined. These blends behave in a closely analogous manner to PVC-PMMA blends already investigated. The results suggest that the PMMA component of the heterogeneous blends is modified in two ways: (1) in a destabilization reaction series initiated by attack of acetate radicals generated in the PVA phase which migrate into the PMMA phase, and (2) in a stabilization reaction involving conversion of ester side groups to acid and subsequently to anhydride ring structures which act as blocking points for depolymerization. The rate of acetic acid production in the blend is less than in PVA degraded alone. The mechanism of degradation of PVA is reconsidered in the light of these results.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1976.170140804
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  • 5
    Electronic Resource
    Electronic Resource
    Degradation of polymer mixtures. VI. Blends of poly(vinyl chloride) with polystyrene (1976)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 14 (1976), S. 353-364 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The degradation of films containing both PS and PVC has been examined by TVA and TG. Stabilization of both polymers, more notably PS, is observed, but the degradation products are the same as when the polymers are degraded alone. Molecular weight measurements indicate a more rapid decrease in the molecular weight of PS when PVC is present. The possibility of grafting or other processes leading to chlorine incorporation in PS has been excluded by the results of experiments using 36Cl-labeled PVC. The mechanisms of possible interactions between the degrading polymers are discussed. Processes involving reaction of chlorine radicals with PS at lower temperatures and reaction of PS radicals with the residue of PVC dehydrochlorination or its decomposition products at higher temperatures appear probable.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1976.170140208
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  • 6
    Electronic Resource
    Electronic Resource
    Degradation of polymer mixtures. VII. Blends of poly(vinyl acetate) with polystyrene (1976)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 14 (1976), S. 603-608 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The degradation of films containing both PVA and PS has been investigated for comparison with the behavior already reported for PVC/PS blends. The presence of PS had little, if any, effect on the behavior of PVA, but PVA had an effect similar to that of PVC on the degradation of PS. Styrene production was retarded in the blend, compared to PS alone, and an increase in the rate of chain scission was observed for a high molecular weight sample. The molecular weight effect, however, was much smaller than in corresponding experiments with PVC/PS blends. Interference with intermolecular transfer in PS is again advanced as the probable explanation of the stabilization of PS.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1976.170140309
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  • 7
    Electronic Resource
    Electronic Resource
    Degradation of polymer mixtures. IX. Blends of polystyrene with polybutadiene (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 2169-2181 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The degradation of cis-1,4-polybutadiene, polystyrene, and blends of PB and PS has been studied by thermogravimetry, thermal volatilization analysis, and differential scanning calorimetry. Volatile products have been investigated and separated by subambient TVA and characterized spectroscopically. In the degradation of the blends, there is no change in the nature of the volatile products of degradation, but the rate of degradation of the PS component is markedly reduced. The PB component is the first to break down, and during the initial period of degradation of the PB, the PS degradation is apparently inhibited. It is suggested that some of the volatile products of decomposition of PB, most notably 4-vinylcyclohexene, may diffuse into the PS phase in the blend and act as radical inhibitors.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160907
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  • 8
    Electronic Resource
    Electronic Resource
    Preparation and degradation of head-to-head PVC (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 2593-2606 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The course of the chlorination reaction of cis-1,4-polybutadiene is dependent on the choice of solvent. When methylene chloride is used, a pure addition reaction of chlorine leads to a polymer with the structure of head-to-head, tail-to-tail PVC. The thermal stability of the head-to-head PVC polymer has been studied by thermal volatilization analysis, thermogravimetry, and evolved gas analysis for hydrogen chloride, and the changes in the ultraviolet (UV) spectrum of the polymer during degradation have been investigated. The head-to-head polymer has a lower threshold temperature of degradation than normal PVC, but reaches its maximum rate of degradation at a higher temperature for powder samples of the polymer under programmed heating conditions. Blends of head-to-head PVC with poly(methyl methacrylate) have also been degraded, and the presence of the head-to-head polymers, like that of normal PVC, results in depolymerization of the PMMA as soon as the dehydrochlorination reaction commences. The mechanism of degradation of head-to-head PVC is discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170161014
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  • 9
    Electronic Resource
    Electronic Resource
    Preparation and degradation of salts of poly(methacrylic acid). I. Lithium, sodium, potassium, and caesium salts (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 3201-3212 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymers of lithium, sodium, potassium, and caesium salts of methacrylic acid have been prepared by free radical polymerization of the respective monomers in methanol solution. The degradation behavior of the polymers has been investigated by thermal volatilization analysis, thermogravimetry, and product analysis. These materials are stable to about 350°C under programmed heating at 10°C/min in vacuo. The principal degradation products are monomer, the corresponding isobutyrate, carbonate, oxide, carbon dioxide, and a fraction of liquid volatiles that is complex and contains a variety of aldehydes and ketones. The mechanism of degradation is discussed in detail.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170161214
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  • 10
    Electronic Resource
    Electronic Resource
    Degradation of polymer mixtures. IV. Blends of poly(vinyl acetate) with poly(vinyl chloride) and other chlorine-containing polymers (1974)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 12 (1974), S. 387-400 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The degradation of the binary polymer blends, poly(vinyl acetate)/poly(vinyl chloride), poly(vinyl acetate)/poly(vinylidene chloride) and poly(vinyl acetate)/polychloroprene has been studied by using thermal volatilization analysis, thermogravimetry, evolved gas analysis for hydrogen chloride and acetic acid, and spectroscopic methods. For the first two systems named, strong interaction occurs in the degrading blend, but the polychloroprene blends showed no indication of interaction. In the PVA/PVC and PVA/PVDC blends, hydrogen chloride from the chlorinated polymer causes substantial acceleration in the deacetylation of PVA. Acetic acid from PVA destabilizes PVC but has little effect in the case of PVDC because of the widely differing degradation temperatures of PVA and PVDC. The presence of hydrogen chloride during the degradation of PVA results in the formation of longer conjugated sequences, and the regression in sequence length at high extents of deacetylation found for PVA degraded alone is not observed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1974.170120211
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