Tacticity-dependent thermal conductivity of single polymer chains

Abstract

While the effect of polymer chain tacticity on crystallinity, glass transition dynamics, and viscoelastic coefficients has been studied, its impact on thermal transport is unknown. Here, molecular dynamics simulations are used to determine the tacticity-dependent thermal conductivity of extended single chains of polypropylene and polystyrene. Chains with ordered tacticity show a threefold enhancement in thermal conductivity compared to chains with random tacticity. A kinetic theory-based model indicates that the enhancement results from a combination of large mean free paths and velocities of energy carriers. This work introduces tacticity control as a strategy to develop thermally conductive polymers.