KINETICS OF LONG-CHAIN BRANCHING IN EMULSION POLYMERIZATION .1. CHAINTRANSFER TO POLYMER

New simulation models to predict the molecular weight distribution in emulsion polymerization that includes chain transfer to polymer are pr oposed. When the frequency of branching is not very large, the kinetic s of emulsion polymerization can be modelled effectively as a large nu mber of semibatch reactors as long as monomer droplets exist and of ba tch reactors after the disappearance of monomer droplets. In such case s, a simulation method based on the branching density distribution pro posed earlier for non-linear polymerizations in homogeneous media show s its versatility to describe the kinetics of non-linear emulsion poly merization. However, the calculated results based on a direct simulati on model that simulates all polymer molecules in each polymer particle clearly show that the fact that each polymer particle consists of a l imited number of polymer molecules must be accounted for as the branch ing density increases. In general, such compartmentalization effects a re important when one considers the molecular weight distribution deve lopment of non-linear polymer chains that are formed in emulsion polym erization.