A MOLECULAR-MODEL FOR SOLID-STATE POLYMERIZATION OF NYLON-6

A theoretical model is developed for the effect of segmental diffusion on reversible step growth polymerization. This model is an adaptation of the molecular model of Chiu et al. for characterizing the Trommsdorff effect in free-radical polymerization. The model is applied to the specific case of solid-state polymerization of spherical pellets of nylon 6. The results of the simulation are found to show qualitative trends as found by Gaymans et al. experimentally. The parameters of the model are curve fitted to their data using an optimal parameter estimation computer code. It is found that the optimal values of the parameters, which can be independently measured, are quite close to the values reported in the literature. The effect of varying the individual parameters on the progress of polymerization is also studied.