MONTE-CARLO SIMULATIONS OF POLYMER DEGRADATIONS .2. DEGRADATIONS INVOLVING RANDOM CHAIN SCISSIONS AND VOLATILIZATION OF LOW-MOLECULAR-WEIGHT PRODUCTS

Polymer degradations involving chain scissions and evolution of low molecular weight products (monomer and oligomers) have been simulated by Monte Carlo procedures to find the most useful parameters to be followed at increasing volatilization and the most significant experiments needed to characterize degradation processes. It has been found that the ratios X(n)/X(n0) and X(w)/X(w0) between number- and weight-average degrees of polymerizations of the polymer samples at any stage of the degradation, and the corresponding values for the undegraded samples, together with the ratio R(m) between the number of molecules in the degraded and undegraded samples, give useful information on the degradation mechanisms. In cases when chain scissions are not completely random, such as when they preferentially occur near particular positions in the polymer chains, it is also convenient to follow the dispersity ratio X(w)/X(n) and changes in the shape of the distribution curves of the degrees of polymerization.