Computer simulation of network formation in free-radical crosslinking copolymerization

Abstract

Abstract A new Monte Carlo simulation model for the kinetics of network formation in free-radical copolymerization of vinyl and divinyl monomers is used to investigate various important property changes during polymerization, such as the whole molecular weight distribution profile, the distribution of crosslink points among various polymer molecules, weight fraction of gel and sol as well as the spatial distribution of the crosslinked polymer chains. This simulation model does not assume a finite reaction system as an approximation for the infinite system, but employs a sampling technique in which polymers are sampled from an infinite number of polymer molecules in the reaction system. The structure of each crosslinked polymer is simulated based on the crosslinking density distribution of the primary polymer molecules that results from a kinetically controlled network formation. The proposed simulation method is quite general and can be applied to various complex polymerization reactions that involve crosslinking and branching in a kinetically controlled system irrespective of reactor types used.