Kinetics of thermal degradation of an alternating copolymer: poly(methylvinylidene cyanide-co-vinyl acetate). Thermogravimetric and gas chromatography—mass spectroscopy studies

Abstract

The thermal behaviour of poly(methylvinylidene cyanide-co-vinyl acetate), an alternating copolymer, has been studied by means of dynamic and isothermal thermogravimetric analysis in the range 280–350°C, and gas chromatographymass spectrometry. The main volatile products are acetic acid, acetonitrile and hydrogen cyanide which indicates that the thermal degradation is mainly an elimination reaction. A kinetic model including, simultaneously, a random and an autocatalytic process, leads to good agreement between experimental and theoretical curves. Kinetic parameters have been calculated. The activation energies are found to be, respectively, 144·1 and 178·6 kJ mol −1 for the random and the autocatalytic process; consequently, the autocatalytic process is slightly predominant at high temperature.