KINETICS OF NETWORK FORMATION IN FREE-RADICAL CROSS-LINKING COPOLYMERIZATION

A new kinetic theory for network formation in free-radical copolymeriz ation of vinyl and divinyl monomers is used to investigate various imp ortant property changes in the postgelation period, such as the weight fraction of gel, the molecular weight distribution, the cross-linking density within sol and gel fractions, the partition of the unreacted pendant double bonds between sol and gel, etc. This theory is based on the cross-linking density distribution among primary polymer molecule s, and the history of the generated network structure is fully account ed for. It is shown clearly that the deviation from the Flory-Stockmay er theory becomes significant as the variance of the cross-linking den sity distribution increases. The present simulation model is quite gen eral and can be applied to various complex polymerization systems that involve cross-linking and branching in a kinetically controlled syste m irrespective of the reactor types used.