Structure of solid poly(tetrafluoroethylene): A computer simulation study of chain orientational, translational, and conformational disorder

The nature of the orientational, translational, and conformational disorder exhibited by poly(tetrafluoroethylene) has been characterized with the help of molecular dynamics calculations based on a new all-atom interaction potential function developed specifically for the perfluoroalkanes. The simulation has identified the following sequence of phenomena, which arise on heating the low-temperature crystalline phase: helical unwinding of chain segments, longitudinal jump diffusion of chains - without gauche defects - followed by generation of gauche defects. These observations accord well with experimental data.