Morphology-influenced thermal conductivity of polyethylene single chains and crystalline fibers

In this paper, the thermal conductivities of polyethylene (PE) single chains and aligned crystalline fibers are calculated using molecular dynamics simulations with the condensed-phase optimized molecular potentials for atomistic simulation studies potential. The segment disorder along the PE chains is found to play an important role in thermal transport in both single PE chains and crystalline PE fibers. In a crystalline PE, thermal conductivity decreases as temperature increases since thermal expansion creates space for chain segment rotation. A critical temperature around 400 K is identified where thermal conductivity decreases by about 90%. The results show that chain morphology is critical to the thermal transport in PE structures.