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  • 1
    Electronic Resource
    Electronic Resource
    Collapsed conformation of poly(methacrylic acid) chain containing nonionic hydrophilic units (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 2183-2190 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymers of methacrylic acid (MAA) and a nonionic hydrophilic monomer N-vinylpyrrolidone (NVP) were synthesized by polymerization in aqueous solution in the absence of metal ions. The NVP content of the copolymers ranged from 2 to 36 mole % with sequences of MAA interrupted at random by a single unit of NVP at all compositions. The pH-induced conformational transition of these copolymers was followed by potentiometric titration and viscosity studies and the results were compared with those of pure poly(methacrylic acid) (PMAA). The negative free energy of transition from the un-ionized compact from to expanded structure showed a gradual decrease with increasing NVP content, and the collapsed conformation observable for PMAA at low degrees of ionization (0 〈 α 〈 0.3) disappeared at NVP contents greater than 15 mole%. These findings are supported by viscosity data. The results suggest that long-range methyl-methyl hydrophobic contacts still possible in higher NVP content copolymers are not sufficient to bring about the collapse of the molecule and a minimum average sequence length of about 20 MAA units is required to compact the molecule. Hydrophilic “shielding” of MAA chains by NVP segments could also partly destabilize the collapsed structure.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160908
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  • 2
    Electronic Resource
    Electronic Resource
    Graft polymers from poly(vinyl chloride) and chlorinated rubber (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 6 (1968), S. 95-107 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Graft polymers from poly(vinyl chloride) (PVC) and chlorinated rubber (CIR) with side chains of poly(methyl methacrylate) (PMMA), poly(methyl acrylate) (PMA), or poly(ethyl methacrylate) (PEMA) were synthesized. For this purpose, a vinyl monomer was polymerized in the presence of small quantities of PVC or CIR with benzoyl peroxide as catalyst. The graft polymers were separated from both homopolymers by precipitation with methanol from methyl ethyl ketone solutions of the reaction products and the grafting efficiency was calculated. The graft polymers were characterized by infrared spectra, elemental analysis, NMR, and osmometric or light-scattering determinations. From the results it is concluded that the PVC or CIR molecules contain side chains of PMMA, PMA, or PEMA. The graft polymers showed higher molecular weights, and the values of second virial coefficient for these polymers were much different from those of the starting polymers.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.150060110
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  • 3
    Electronic Resource
    Electronic Resource
    Microbead polymerization of styrene-divinylbenzene with sulfated poly(vinyl alcohol) suspending agent (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 9 (1971), S. 805-807 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.150090319
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  • 4
    Electronic Resource
    Electronic Resource
    Graft polymers: Chain transfer and branching (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2681-2691 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The vinyl monomers, methyl methacrylate, ethyl methacrylate, and methyl acrylate were polymerized in the presence of chlorinated rubber or poly(vinyl chloride) in homogeneous solution with benzoyl peroxide as catalyst. A graft polymer was formed by a chain-transfer reaction involving the growing polymer radicals to the backbone of chlorinated rubber or poly(vinyl chloride), in addition to homopolymer from the monomer. The homopolymer was isolated from the polymer mixture by fractional precipitation from methyl ethyl ketone solution with methanol as precipitant. The chain-transfer constants for the branching reactions were evaluated. The ratios kp/(kt)1/2 for the grafting reactions were obtained by a correlation of chain-transfer constants with the extent of branching. The chain-transfer data were correlated on the basis of an extension of the Q-e scheme of Alfrey and Price to polymer-polymer transfer reactions. Specific effects due to the backbone are found to have considerable influence on the course of the chaintransfer reactions and kp/(kt)1/2 of the grafting reactions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.150051018
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