Chain packing and phase transition of cubic-lattice polymer systems with orientation-dependent interactions

Abstract

The author examines the effects of orientation-dependent interactions on the chain packing and phase transition of bulk polymer systems, using Monte Carlo simulations on cubic-lattice chains. The magnitude of orientation-dependent attractions relative to the chain flex energy emerges as a very important parameter that affects the chain packing in the polymers melts and their disorder-order transitions. In the presence of relatively strong anisotropic interactions between the segments, the disordered polymer melts contain small 'clusters' comprising straight trans chain segments from the neighboring chains. As the temperature is lowered, these clusters grow rapidly in their sizes and dominate the disorder-order transitions.