engleski

Free-radical-initiated copolymerization of 2-chlorostyrene, 4-chlorostyrene and 2, 6-dichlorostyrene with maleic anhydride

The title copolymers have been prepared by the free-radical-initiated copolymerization of 2-chlorostyrene (2-ClSt), 4-chlorostyrene (4-ClSt) and 2, 6-dichlorostyrene (2, 6-DClSt) with maleic anhydride (MAn) in toluene at 650C. Copolymers of chlorinated styrenes with MAn prepared under different monomer-to-monomer ratios in the feed have alternating composition. In all cases the mixture of comonomers forms charge-transfer complex monomers (CTC). Initial rate of copolymerization increases with the increase of electron donors in the comonomer feed, and the highest rates were at the equimolar ratios of comonomers in the feed. The thermal stability of the polymers was measured by thermogravimetric analysis in nitrogen. Homopolymers decompose by one-step mechanism while copolymers are more thermostable and decompose by two-step mechanism. Tg’s of homopolymers are lower than Tg’s of copolymers. The number and weight average molecular weights of chlorinated copolymers are higher than those of the corresponding homopolymers.

mechanism of Copolymerization; charge-transfer-complex monomers; poly(2-chlorostyrene-co-maleic anhydride); poly(4-chlorostyrene-co-maleic anhydride); poly(2; 6-dichlorostyrene-co-maleic anhydride); thermal properties; rate of copolymerization

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