A simple lattice model for the basal interface in compressible semi-crystalline polymers

The basal interfacial regions of the laminar crystalline structures growing at moderate undercoolings in melt-crystallizing polymers, are modeled by accommodating a linear chain in a cubic lattice. The model extends previous treatments in that a finite compressibility is also accounted for. It is found that, due to the presence of density gradients: (a) compressibility is responsible of order 10% contributions to the overall basal surface tension, σe, in realistic conditions, and (b) the corresponding tight folding energies required to match the observed values of σe decrease by order 30%.