MONTE-CARLO SIMULATION OF POLYMER NETWORK FORMATION WITH COMPLEX CHEMICAL-REACTION MECHANISM - KINETIC APPROACH ON CURING OF EPOXIDES WITH AMINES

A new algorithm of Monte Carlo (MC) simulation has been developed for network formation by a kinetic approach. This method is very general a nd can be directly applied to various systems with a complex chemical reaction mechanism. The strategy of the MC method is divided into two steps, selecting the type of the reaction mechanism and then choosing the reacting molecules. This makes it possible to accomplish the simul ation in a reasonable time. Then the systems of epoxy resins cured wit h primary amines with a substitution effect and etherification were an alyzed by this method. The changes of the structure, such as the molec ular weight distribution of polymers, gel fraction, and cycle rank, we re calculated, and the gel point was determined by the method of reduc ed average molecular weight. It is found that, if the effect of topolo gy is not taken into account, very few times of the intramolecular rea ctions occur before gelation for a large finite system. The gel point and the average molecular weight profiles simulated are well consisten t with those by another kinetic approach and experimental data, and th e changes of the molecular weight distribution (MWD) depend on the rat e of etherification.