Abstract
The thermal degradation of polymethylmethacrylate was proceeded only by end initiation (k1, rate constant) under 300°C, but in accompany with random initiation (k1, rate constant) above that. The initial rate of volatilization was derived from the statistical consideration of chain mechanism and applied to our experimental results. Activation energy for k2 and probability of depropagation were computed as 51 kcal/mol and 0.9994. Comparing the degradation of polymethylmethacrylate to that of polystyrene following to the same initiation, the former is rather small in k2, but very much larger in the kinetic chain length than the latter.These can be understood on the basis of their molecular structure.
