Engineering polymers with metal-like thermal conductivity—Present status and future perspectives

Abstract Common polymers are thermal insulators. Turning polymer insulators into heat conductors is of fundamental interest and technological importance. Thermally conductive polymers may replace traditional metal heat conductors as lightweight and corrosion-resistant heat dissipators. In this review, we highlight recent progresses in developing polymers with metal-like thermal conductivity and discuss the understanding of thermal transport mechanisms in polymers. We use polyethylene as a model and address how thermal conductivity of polyethylene is influenced by structural parameters such as bond strength, chain orientation, molecular weight, crystallinity, and crystallite size. We review advanced strategies for developing thermally conductive polymers, e.g., mechanical stretching, extrusion, electrospinning, and template-assisted methods. We highlight how thermally conductive polymers provide new possibilities for future thermal management applications. Finally, we discuss future challenges and opportunities in designing and synthesizing polymers with metal-like thermal conductivity.