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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 58 (1999), S. 533-539 
    ISSN: 1572-8943
    Keywords: group transfer polymerisation ; H–H linkage ; molecular mass ; random chain scission ; weak linkages
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The paper describes the effect of molecular mass and copolymer composition on thermal behaviour of homopolymers and copolymers of glycidyl methacrylate and methyl methacrylate. The polymerisation was done by using group transfer polymerization (GTP) and free radical techniques. A multistep decomposition was observed in polymers prepared by free radical technique indicating the presence of weak linkages in the backbone. Copolymers prepared by GTP had fewer weak sites and degraded in single step by a random chain scission.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 3279-3289 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several copolymers of 2-hydroxyethyl methacrylate (HEMA) with methyl acrylate (MA), ethyl acrylate (EA), n-butyl acrylate (BA), and methyl methacrylate (MMA) were prepared at 70°C in nitrogen atmosphere using 0.2% (w/v) benzoyl peroxide as initiator. The copolymer composition was evaluated by estimation of hydroxyl group in the copolymers. Intrinsic viscosity of HEMA-EA, HEMA-BA, and HEMA-MMA copolymers was determined at 35°C in dimethyl formamide. Molecular weight distribution of copolymer samples was evaluated by gel permeation chromatography. Thermal behavior of the copolymers was investigated by dynamic thermogravimetry. Thermal stability decreased on increasing HEMA content in MA, EA, and BA copolymers. However, a reverse trend was observed in HEMA-MMA copolymers.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 1487-1494 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polypyromellitimides were prepared by the reaction of di(4-aminophenyl) ether (E)/di (4-aminophenyl) methane (M), and pyromellitic dianhydride in dimethylformamide, followed by thermal cyclization in a nitrogen atmosphere. Copolyimides were obtained by taking different molar ratios of diamines in the initial monomer feed. Differential scanning calorimetric, thermogravimetric analysis, and thermally stimulated current studies were carried out on these samples. It was concluded that the dielectric relaxation in these copolymers is due to trapping of the charge carriers. The dielectric relaxation parameters and activation energies were also calculated.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 163-172 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polybenzimidazoles (PBI) with p-phenylene and/or cis-vinylene groups in the backbone were prepared from terephthalic acid (T), maleic acid (M), and 3,3′ diamino-benzidine tetrahydrochloride dihydrate (DAB) in poly(phosphoric acid) (PPA). Five polymer samples were prepared by varying the M:T molar ratios in the following order: 1:0, 1:1, 2:1, 1:2, and 1:4. The polymers were characterized by intrinsic viscosity, density, electronic fluorescence, and IR spectra. The effect of composition on the solubility of the polymers in various organic solvents was also investigated. The relative thermal stability of the polymers was evaluated by dynamic thermogravimetry in air and polybenzimidazoles (PBI) with cis-vinylene groups were found to be less stable.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 1419-1433 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This article describes the synthesis of N,N′-bis(3,3′-maleimidophenyl) sulfone (S) and its Michael addition products with (4,4′-diaminodiphenyl) methane (S-M), 4,4′-diaminodiphenyl ether (S-E), (3,3′-diaminodiphenyl) sulfone (S-DDSm), (4,4′-diaminodiphenyl) sulfone (S-DDSp), (3,3′,3″-tris aminophenyl) phosphine oxide (S-TAP), and 9,9-bis(p-aminophenyl) fluorene (S-B). Curing behavior of these bisimides was investigated by differential scanning calorimetry. Activation energy of curing reaction was determined by using isothermal and multiple heating rate method. Thermal stability of bisimides was evaluated by thermogravimetric analysis. Better char yields were obtained in S-TAP resins.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 1885-1891 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 14 (1976), S. 973-980 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Homopolymers and copolymers containing the polybenzimidazoles ring were prepared from terephthalic acid (T), fumaric acid (F), and 3,3′-diaminobenzidine tetrachloride (DAB) in polyphosphoric acid. The polymers were characterized by viscometry, infrared spectroscopy, and nitrogen analyses. The effect of copolymer composition on the ultraviolet and visible spectra, solubility in various solvents, and density was also investigated. The relative thermal stability of the various polybenzimidazoles was investigated by using dynamic thermogravimetry in air. Polybenzimidazole derived from terephthalic acid was most stable, and the introduction of aliphatic residues resulted in a decrease in thermal stability. However, the homopolymer of fumaric acid was more stable than the copolymers of fumaric acid and terephthalic acid.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 703-713 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyimides with different proportions of m-phenylene and p-phenylene (or p,p′-biphenylene) were prepared by polymerizing different molar ratios of m-phenylene diamine and p-phenylene diamine (or p,p′-diaminobiphenyl) with pyromellitic dianhydride in dimethylformamide at 0°C. Chemical cyclodehydration of polyamic acids resulted in the corresponding polyimides. Polymers were characterized by infrared (IR), viscosity, and density measurements. Viscosity and density of polymers decreased with an increase on m-phenylene groups in the backbone. The thermal and thermooxidative stabilities were investigated by dynamic thermogravimetry. Stability decreased when m-phenylene groups were introduced in the backbone.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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