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 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 indicated that the copolymers decompose in the 260–400°C range.

Keywords:

• trisubstituted ethylenes
• radical copolymerization
• styrene copolymers

Acknowledgments

We are grateful to acknowledge that the project was partly supported by the research and equipment grants from the National Science Foundation's DUE Grant (No. 9455681), Coating Industry Education Fund (CIEF), Chicago Society of Coatings Technology, the DePaul University Research and Quality of Instruction Councils, and Office of Sponsored Programs and Research.