NETWORK FORMATION IN EMULSION CROSS-LINKING COPOLYMERIZATION

A new Monte Carlo simulation model for the kinetics of emulsion copolymerization of vinyl and divinyl monomers is proposed. The polymer particles formed in emulsion polymerizations usually consist of less than 10(8) monomeric units; therefore, the kinetic behavior of all polymer molecules in each polymer particle can be simulated easily using the Monte Carlo method. It was found that the molecular weight distribution development in emulsion cross-linking copolymerization is completely different from that in homogeneous polymerizations. A drastic change in molecular weights at the gel point that is characteristic of homogeneous polymerizations is not a requisite for the microgel formation. It is expected that there are cases in which the gel point cannot be determined experimentally, and a new definition for gel may be required for emulsion polymers.