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Copolymerization and copolymers of 2, 4, 5-tribromostyrene with styrene and acrylonitrile

2, 4, 5-Tribromostyrene (TBSt) was copolymerized with styrene (St) or acrylonitrile (AN) in toluene solution using 2, 2′-azobisisobutyronitrile as free radical initiator. The copolymerization reactivity ratios were found to be for the system TBSt/St r1 = 1.035 ± 0.164 (TBSt) and r2 = 0.150 ± 0.057 (St), and for the system TBSt/AN r1 = 2.445 ± 0.270 (TBSt) and r2 = 0.133 ± 0.054 (AN). The e and Q values were also calculated. The initial copolymerization rate, Rp, for both systems linearly increases as the content of TBSt in the monomer mixture increases. However, these values are somewhat higher when AN was used as a comonomer. A similar behavior has also been established for the course of the copolymerization reactions to high conversion. The resulting copolymers and TBSt-homopolymer show similar thermal stabilities of polystyrene. However, the glass transition temperature increases markedly with increasing TBSt content.

tribromostyrene; styrene; acrylonitrile; copolymerization; copolymers; copolymerization reactivity ratios; glass transition; thermal stability

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