Gel point and mechanism of gel formation in copolymers from free-radical crosslinking polymerization of vinyl/divinyl monomers

After discussing the results from the computer simulations of gel point in the vinyl/divinyl monomer free-radical crosslinking polymerization by several typical models, the authors proposed that gel point be distinguished from mechanism of gel formation, The criteria of gel point is the appearing of the macromolecule whose average crosslinking density is equal to 1/<(DP)over bar>(pw). However, the gel formation can have two processes of nucleation and growth, where the condition of nucleation is that the average crosslinking density in one macromolecule of a sol becomes 1/<(DP)over bar>(pw).