Novel Copolymers of Styrene and Alkyl Ring‐Substituted Methyl 2‐Cyano‐3‐phenyl‐2‐propenoates

Abstract

Electrophilic trisubstituted ethylene monomers, alkyl ring substituted methyl 2‐cyano‐3‐phenyl‐2‐propenoates, RC6H4CH[dbnd]C(CN)CO2CH3, where R is 2‐methyl, 3‐methyl, 4‐methyl, 4‐isopropyl, and 2,5‐dimethyl were synthesized by piperidine catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and methyl cyanoacetate, and characterized by CHN elemental analysis, IR, 1H and 13C NMR. Novel copolymers of the ethylenes and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (AIBN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C NMR, GPC, DSC, and TGA. High Tg of the copolymers in comparison with that of polystyrene indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 260–400°C range.