[10a-W371-1~12] 22.1 Joint Session M "Phonon Engineering"

△ [10a-W371-11] Ab initio exploration of high thermal conductivity polymer crystals

〇(M2)Keishu Uchimura¹, Tom Ichibha², Ryo Maezono², Kenta Hongo^3,4,5 (1.Mater. Sci., JAIST, 2.Info. Sci., JAIST, 3.RCACI., JAIST, 4.NIMS, 5.PRESTO, JST)

Keywords:Polymer, Ab initio study, Thermal conductivity

Lattice thermal conductivities (LTC) for a subset of polymer crystals from the Polymer Genome Library were investigated to explore high LTC polymer systems. We employed a first principles approach to evaluating a phonon lifetime within the third-order perturbation theory combined with density functional theory, and then solved the linearized Boltzmann transport equation with single-mode relaxation time approximated by the computed lifetime. Typical high LTC polymer systems, polyethylene crystal and fiber, were benchmarked, which is reasonably consistent with previous references, validating our approach. Applying it to a number of polymer crystals, for the first time, we discovered that beta phase of Poly(vinylidenesurely fluoride) (PVF-beta) crystal at low temperature has the highest LTC among all the cases considered. We also found the LTC correlating with curvature of energy-volume plot. The curvature would be used as a descriptor for further exploration of high LTC polymer crystals by means of a data-driven approach beyond human-based one.