Novel Copolymers of Trisubstituted Ethylenes and Styrene. II. Halogen Ring‐Substituted Ethyl 2‐Cyano‐1‐oxo‐3‐phenyl‐2‐propenylcarbamates

Abstract

Abstract Electrophilic trisubstituted ethylenes (TSE), halogen ring‐substituted ethyl 2‐cyano‐1‐oxo‐3‐phenyl‐2‐propenylcarbamates, RC6H4CH˭C(CN)CONHCO2C2H5 (where R is 3‐Br, 4‐Br, 3‐Cl, 4‐Cl, 2‐F, 3‐F, and 4‐F) were prepared and copolymerized with styrene (ST). The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and N‐cyanoacetylurethane, and characterized by CHN analysis, IR, 1H, and 13C NMR. All the ethylenes were copolymerized with ST (M1) in solution with radical initiation (AIBN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H, and 13C NMR. The order of relative reactivity (1/r 1) for the monomers is 2‐F (3.81) > 3‐Cl (1.36) > 4‐Br (1.31) > 3‐Br (1.13) > 4‐F (0.90) > 3‐F (0.63) > 4‐Cl (0.37). Higher T g of the copolymers in comparison with that of polystyrene indicates decrease in chain mobility of the copolymer due to the high dipolar character of the TSE structural unit. Gravimetric analysis indicated that the copolymers decompose in the range 303–319°C. Keywords: Trisubstituted ethylenesRadical copolymerizationStyrene copolymersCarbamates Acknowledgments We are grateful to acknowledge that the project was partly supported by the Coatings Industry Education Fund (CIEF), Chicago Society of Coating Technology and Office of Sponsored Programs and Research of DePaul University.