KINETIC-MODEL OF THERMAL-DEGRADATION OF POLYMERS FOR NONISOTHERMAL PROCESS

A new kinetic model was developed to describe the thermal degradation behavior of polymers. The model was applied to predict the degradation of poly(methyl methacrylate) (PMMA) blended with propyl ester phospha zene (FR). The results showed that the thermal degradation mechanism o f pure PMMA was dominated by zero- and first-order reactions. For PMMA blended with FR, the thermal degradation mechanism was dominated by f irst-and second-order reactions due to the formation of anhydride from the ester groups of PMMA. In addition, the major thermal degradation temperature of blends was gr eater than pure PMMA. By using our model, the activation energy of the thermal degradation PMMA was calculated to be 180 kJ/mol; this activation energy increased as FR was added to PMMA. (C) 1997 John Wiley & Sons, Inc.