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  • 1
    Electronic Resource
    Electronic Resource
    Effect of nucleating agents upon the kinetics of polybutene-1 crystallization (1981)
    Springer
    Polymer bulletin 5 (1981), S. 635-641 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The influence of various nucleating agents on the crystallization parameters of polybutene-1 is reported. Isothermal crystallization is investigated by differential scanning calorimetry. The morphology induced by the differents nucleating agents has been observed by hot stage polarizing microscopy. It has been stated that the addition of nucleating agent affects the crystallization rate, dimension and homogeneity of spherulitic sizes. The induction time ti, the semicrystallization time t1/2, the crystallization rate constant K, and the Avrami coefficient n were measured and related to the different characteristics of the specimens. Because of the fractional values of n obtained in this study, it is not possible to propose well determined mechanisms of crystallization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00255304
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  • 2
    Electronic Resource
    Electronic Resource
    Graft polymerization of 4-vinylpyridine onto cellulosic fibres by the ceric ion method, I. The reaction time effect (1990)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 178 (1990), S. 109-118 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß der Reaktionsdauer auf die mit Cer(IV)-Ionen initiierte Pfropfung von 4-Vinylpyridin (4-VP) auf partiell carboxymethylierte Cellulose (PCMC) mit verschiedenen Substitutionsgraden (D.S.) wurde untersucht. Zum Vergleich wurde dasselbe Monomere auf Baumwolle und mercerisierte Baumwolle gepfropft. Die Pfropfparamater dieser Polymerisationsreaktionen wurden bestimmt. Der Pfropfungsgrad (G) war bei PCMC signifikant höher als bei Baumwolle und mercerisierter Baumwolle. Der durch Röntgenbeugung ermittelte Kristallisationsgrad der Pfropfcopolymeren war niedriger als der von unmodifizierter Baumwolle. Der Einfluß der Reaktionszeit auf die Pfropfung von Baumwolle mit 2-Vinylpyridin wurde ebenfalls untersucht.
    Notes: A study was made of the time affecting the ceric ion induced grafting of 4-vinylpyridine (4-VP) onto partially carboxymethylated cotton (PCMC) having different degrees of substitution (D.S.). For comparison the same monomer was grafted onto cotton and mercerized cotton. The grafting parameters of these copolymerization reactions were determined. The graft yields for PCMC were significantly higher than those for unmodified cotton and mercerized cotton. The degree of crystallinity of the graft copolymers and of the unmodified cotton and PCMC samples was determined by the X-ray method. The crystallinity index decreased with the presence of grafted polymer. The reaction time effect of the grafting of 2-VP on cotton was also studied.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1990.051780108
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  • 3
    Electronic Resource
    Electronic Resource
    Graft polymerization of 4-vinylpyridine onto cellulosic fibres by the ceric ion method, IIPart I cf.14.. The ph effect (1990)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 178 (1990), S. 119-129 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß des pH-Wertes auf die mit Cer(IV)-ammoniumnitrat initiierte Pfropfpolymerisation von 4-Vinylpyridin (4-VP) auf Cellulose und partiell carboxymethylierte Cellulose (PCMC) in verdünnter Salpetersäure wurde untersucht. Die Abhängigkeiten von Pfropfausbeute (GE), Pfropfungsgrad (G), Pfropfhäufigkeit (GF) und Cerionenverbrauch (Ce(IV)c) von der Salpetersäurekonzentration wurden ermittelt. Bei pH = 1 sind Gesamtumsatz und Pfropfumsatz am größten; wird die Nitratkonzentration konstant gehalten (0,86 mol/1), läßt sich der Pfropfumsatz noch erhöhen. Zum Vergleich wurden einige Experimente mit Cersulfat als Initiator durchgeführt.
    Notes: The effect of pH on the graft polymerization of 4-vinylpyridine (4-VP) onto cellulose and on partially carboxymethylated cotton (PCMC) initiated by ceric ammonium nitrate (CAN) in dilute nitric acid was examined. The grafting parameters grafting efficiency (GE), graft yield (G), graft frequency (GF), and ceric ion consumption (Ce(IV)c) were studied as a function of nitric acid concentration. Also the effect of pH on the graft polymerization was examined and the total nitrate ion concentration was maintained high and constant at 0.86 mol/1 by addition of sodium nitrate. Maximum grafting and total conversion occurred at pH 1, but these values were smaller than the ones obtained in the previous case. For comparison some experiments were carried out using ceric sulfate as initiator.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1990.051780109
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  • 4
    Electronic Resource
    Electronic Resource
    Miscibility in blends of polycarbonate and an aromatic polyester (1983)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 184 (1983), S. 1741-1747 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Blends of the polycarbonate of bisphenol-A (PC) with polyacrylate (PA), an aromatic polyester formed from bisphenol A and terephthalic acid/isophthalic acid, were prepared by both melt and solution casting, and their transitional behaviour was examined by differential scanning calorimetry (DSC) and thermo-optical analysis (TOA). Each blend composition was found to have a single glass transition temperature by DSC and by TOA. This result suggests that polycaronate and polyarylate form blends containing a single amorphous phase. Ester-carbonate interchange reactions during melt-mixing were experimentally found to be unimportant. Melting point depression was used to estimate the blend interaction parameter χ12.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1983.021840817
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  • 5
    Electronic Resource
    Electronic Resource
    Characteristic ratio of a 1,4-poly(2,3-dimethyl butadiene) (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 173-174 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.180180116
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  • 6
    Electronic Resource
    Electronic Resource
    Characterization of ethylene-vinyl acetate copolymers by viscometry and GPC (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 180 (1979), S. 2749-2751 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.021801116
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  • 7
    Electronic Resource
    Electronic Resource
    Effect of molecular weight on the crystallization kinetics of isotactic poly(1-butene) (1982)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 183 (1982), S. 721-729 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Isothermal crystallization of isotactic poly(1-butene) fractions by calorimetry and microscopy was studied for a range of molecular weights from 96 000 to 964000. An Avrami exponent of 2 was found indicating a two-dimensional growth rate of the crystal, following a predetermined nucleation mode, proving that such an exponent is independent of both temperature and molecular weight. The temperature and molecular weight dependence of the growth rate of spherulites and overall crystallization rates was analyzed by means of the theoretical expression given by Hoffman and Lauritzen. The product of the lateral and basal surface free energies of the crystallites, σ·σe, increases with molecular weight and approaches its limiting values when a certain molecular weight is attained.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1982.021830321
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  • 8
    Electronic Resource
    Electronic Resource
    Ceric ion consumption in graft copolymerization of methacrylonitrile/methacrylate mixtures onto amylomaize (1992)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 193 (1992), S. 2189-2198 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A study on the Ce(IV) consumption in the graft copolymerization of methacrylonitrile/n-alkyl methacrylate mixtures methyl, ethyl and butyl methacrylate/methacrylonitrile (MMA/MAN, EMA/MAN and BMA/MAN) was carried out. Ce(IV) consumption increased with increasing mole fraction of the methacrylate in the monomer feed and with increasing the n-alkyl group length of the methacrylate, but in no case the consumption was total. The molecular weight distribution of the copolymers was obtained through gel-permeation chromatography. For all systems investigated, both number-average molecular weight (Mn) and weight-average molecular weight (Mw) increased with increasing methacrylate concentration in the monomer feed. The ratios Mw/Mn increased in the following order: MMA/MAN 〈 EMA/MAN 〈 BMA/MAN. For the MAN/MMA system, the number of grafted chains (in mmol) increased as the methyl methacrylate content increased in the monomer feed, and for the MAN/EMA and MAN/BMA systems, this parameter presented a maximum value. The number of D-anhydroglucose units per grafted chain (frequency) decreased with increasing methacrylate concentration in monomer feed for the MAN/MMA system, and this parameter reached a minimum value at a methacrylate mole fraction of 0,5 for the other two systems.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1992.021930902
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  • 9
    Electronic Resource
    Electronic Resource
    Melt rheology of high impact polystyrenes at high shear stresses (1982)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 22 (1982), S. 365-369 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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 study of the theological properties of commercial polystyrenes, (PS), and high impact polystyrenes (HIPS), is made in the range of shear stresses of practical interest in industrial polymer processing.A general viscosity-shear rate-temperature relationship is defined for these products, with a power law exponent of n = 0.3 and an activation energy of 27 Kcal/mol.The fluid elasticity is studied in terms of steady state shear compliance. An expression relating shear compliance, viscosity and molecular weight distribution is obtained for HIPS. As in other two-phase systems, a decrease in elasticity with viscosity is observed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760220607
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  • 10
    Electronic Resource
    Electronic Resource
    Determination of capillary entrance pressure losses and first normal stress difference in polystyrene and high impact polystyrene melts (1981)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 21 (1981), S. 307-311 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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: In industrial polymer processing, polymeric melts give rise to shear stresses above 105 dynes/cm2. For the determination of rheological properties and particularly melt elasticity, only the capillary type instrument is applicable to this range. In this paper, a comparative experimental study of the first normal stress difference, obtained from end pressure losses, entrance pressure losses and die swell is reported for polystyrene and high impact polystyrene. Good agreement between results from the three methods of measurement was obtained. The results are in accordance with literature data obtained using a capillary rheometer. It is seen that the values of first normal stress difference are greater in polystyrene than in high impact polystyrene.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760210509
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