Random sampling technique to predict the molecular weight distribution in nonlinear polymerization

SUMMARY Comprehensive accounts for the newly proposed concept of the random sampling technique are given in detail. This techniques involves random sampling of polymer molecules from an infinite number of polymeric species in the reaction mixture, and can provide a deeper insight into the complex molecular buildup processes such as those involving branching, crosslinking, and degradation reactions. For simpler cases, the analytical solutions for the molecular weight distribution can be obtained. By combining this technique with the Monte Carlo method, one obtains a very powerful simulator that can be applied to virtually any type of nonlinear polymer formation (or degradation) irrespective of the reactor types used, as long as the chain‐length and structural dependences of the reaction kinetics can be neglected. In the Monte Carlo simulations, we can observe the structure of each polymer molecule directly so that very detailed structural information, including the spatial distribution of polymer chains, can be obtained in a straightforward manner. Several types of nonlinear polymerization schemes are used to illustrate the fundamentals of the presented technique.