The copolymerization of 1-alkylvinazenes with styrene

Copolymers are formed between styrene and 1-alkyl-4,5-dicyano-2-vinylimidaz oles (1-alkylvinazenes). The reactivity ratios for the 1-ethylvinazenes are determined to be high, but also appear to vary with feed composition, with low feed ratios of 1-ethylvinazene giving r(EtVz)=35 +/- 6 and r(Sty)=0.07 7 +/- 0.029, whereas at higher 1-ethylvinazene feed fractions, r(EtVz)=2.5 +/- 2 and r(Sty)=0.089 +/- 0.021. Mediation of the 1-methylvinazene/styrene copolymerization with 2,2,6,6-tetramethylpiperidine-N-oxide (TEMPO) leads to a more controlled polymerization which moves closer to ideal copolymeriz ation behavior. The copolymers form with polydispersities approaching 1.5, suggesting bimolecular termination kinetics. The copolymers comply with the Fox relation for T-g.