Kinetic gelation with and without initiators: A two-dimensional Monte Carlo study

The authors simulate a mixture of bifunctional and tetrafunctional molecules which may form bonds, on a triangular lattice, both with and without the help of free radicals. The model of Herrmann et al. (1982, 1983) and normal bond percolation are two special limits of the model. The authors determine the gel point, the fraction of matter in the infinite network or gel, and the weight-average degree of polymerisation, as a function of time. For radical-initiated gelation, the observed cluster distribution confirms the conclusion of Herrmann et al., that this model is different from random restricted-valence percolation. However, the gel point is found to decrease with increasing concentration of bifunctional molecules, quite unlike the behaviour observed in three dimensions.