Novel copolymers of vinyl acetate. 4. Halogen ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates

Novel copolymers of vinyl acetate and halogen ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2C2H5 (where R is 2-Br, 3-Br, 4-Br, 2-Cl, 3-Cl, 4-Cl, 2-F, 3-F, 4-F, 2,3-dichloro, 2,4-dichloro, 2,6-dichloro, 3,4-dichloro, 2,4-difluoro, 2-bromo-3,4-dimethoxy) were prepared in solution with radical initiation at 70C. The propenoates were synthesized by the piperidine catalyzed Knoevenagel condensation of halogen ring-substituted benzaldehydes and ethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. Thermal behavior of the copolymers was studied by DSC (Tg) and TGA. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 159-500ºC range with residue (8.8-15.2 wt%), which then decomposed in the 500-650ºC range.