Analysis of the linear methods of determining copolymerization reactivity ratios, 11. Copolymerization of styrene with methyl α‐cyanocinnamate and fumaroyldipyrrolidone

The composition of copolymers was determined as a function of the monomer feed for two systems: styrene/methyl a‐cyanocinnamate in toluene and styrene/fumaroyldipyrrolidone in dimethyl sulfoxide both at 60°C with 2,2′‐azoisobutyronitrile (AIBN) as initiator. To ascertain the accuracy of reaction modelling in terms of the classical and the penultimate model, the extended linearized forms of both models were applied. The styrene/methyl a‐cyanocinnamate system was found to copolymerize non‐classically; the two‐parameter penultimate model described properly the experimental data yielding r'1/r1 ≈ 3–6. The styrene/fumaroyldipyrrolidone system showed only a slight penultimate effect. However, in this case, the terminal model gave a better fit of experimental data.