Strain-induced oriented crystallization of UHMWPE: Enhanced thermal conductivity through molecular chain alignment

Thermal conductivity of bulk polymers can be enhanced by strain-induced oriented crystallization. This work reports a three-step solution-free fabrication process to promote a polymer film’s molecular chain alignment. First, the mobility of molecular chain is promoted by equilibrating the film at an elevated temperature. Second, the film is mechanically drawn at controlled strain level, strain rate, and temperature. Third, the stretched film is rapidly cooled to stabilize its microstructure. Parametric studies have identified that promoting intermolecular fringed-micelles with preferential orientation without unfolding the intramolecular folded-chain nucleus can maximize its in-plane thermal conductivity.