Novel Copolymers of Styrene and Alkyl Ring‐Substituted 2‐Cyano‐N,N‐dimethyl‐3‐phenyl‐2‐propenamides

Electrophilic trisubstituted ethylene monomers, alkyl ring‐substituted 2‐cyano‐N,N‐dimethyl‐3‐phenyl‐2‐propenamides, RC6H4CH[dbnd]C(CN)CON(CH3)2 (where R is H, 2‐CH3, 3‐CH3, 4‐CH3, 4‐CH2CH3, 4‐CH(CH3)2, 4‐CH2CH2CH2CH3, 2,4‐diCH3, 2,5‐diCH3,), were synthesized by potassium hydroxide catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and N,N‐dimethyl cyanoacetamide, 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, ABCN 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 T g 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 in...