Studies on Mechanism of Grafting of Polystyrene on Elastomer Backbone
作者:
V.K. Gupta,
G.S. Bhargava,
K.K. Bhattacharyya,
期刊:
Journal of Macromolecular Science: Part A - Chemistry
(Taylor Available online 1981)
卷期:
Volume 16,
issue 6
页码: 1107-1116
ISSN:0022-233X
年代: 1981
DOI:10.1080/00222338108063219
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
The mechanism of grafting of polystyrene on a polybutadiene (PB) backbone during the preparation of impact-resistant polystyrene was studied by withdrawing samples during propolym-erization from beginning of the reaction to about 25% conversion. Good separation of the “elastomer and graft” fraction of the polymer from the free polystyrene part could be achieved by using 0.24 volume fraction of methanol in (MEK + benzene) + methanol solvent-nonsolvent. IR analysis of the grafted fraction showed that the microstructure of the elastomer remained unaltered. The unsaturation of the samples studied through the bromine number as well as by the perbenzoic acid number was also found to remain unchanged. Formation of free polystyrene started with the onset of polymerization and was faster. During prepolymerization, 80% of styrene converted constantly to form free polystyrene and 20% went into the grafted polymer. The results indicate that grafting is initiated through proton abstraction at the α-carbon of butadiene, most probably by initiator radicals. The grafted polystyrene chains possibly are shorter than free polystyrene chains.
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