INVESTIGATION OF THE DECOMPOSITION OF COPOLYMERS OF STYRENE AND MALEIC-ANHYDRIDE USING THERMOGRAVIMETRIC ANALYSIS

The thermal decomposition of several copolymers of styrene (St) or α-methylstyrene (AMS) and maleic anhydride (MAn) were studied by non-isothermal TG in inert atmosphere. From TG data in the temperature range 573-723 K, the kinetic decomposition parameters were calculated using Ozawa's method. The activation energy of decomposition and pre-exponential factor for St/MAn copolymers were: EA = 191-225 kJ mol-1, log A = 19.65-22.56 min-1 and for an AMS/MAn copolymer EA = 266 kJ mol-1, log A = 26.84 min-1, with a random degradation as the best-fitted mechanism for both types of copolymers. The relation between experimental results and structural characteristics of the copolymers is discussed. © 1990.