Morphological consequences of interchange reactions during solid state polymerization in oriented polymers

Interchange reactions during solid-state polymerization (SSP) can cause significant morphological changes in the intercrystalline regions. A coarse-grained model has been formulated for the effect of these reactions on the topological distribution of chains in the intercrystalline regions of oriented polymer morphologies. It includes a novel thermodynamic scheme, coupled with a Monte Carlo simulation, based on rotational isomeric states, of confined chains to determine the relative probabilities of topologically different reaction outcomes. The results show the role of intrinsic molecular rigidity on interchange-reaction dictated interconversions of bridges and loops during SSP of different polymers. The scheme presented here can serve to identify, via gedanken experiments, appropriate semirigid polymers for synthesis and processing to produce morphologies for high mechanical performance. It can also be used to determine the above-ir, mechanical properties of noncrystalline domains, with a known initial topological distribution of chains, as well as the equilibrium distribution of these chains.