A comparison of the spectra of the monomers, copolymers, and polyvinyl acetate with the spectra of ring-unsubstituted ethyl 2-cyano-3-phenyl-2-propenoate -VAC shows, that the reaction between the ECPP monomers and VAC is a copolymerization. Information on the degradation of the copolymers was obtained from thermogravimetric analysis. Decomposition of the copolymers in nitrogen occurred in two steps, apparently due to acetic acid elimination in 150-340ºC range followed by more slow decomposition of formed residue (15.1-1.5 wt%), which then decomposed in the 500-650ºC range.