High Thermal Conductivity Ultra-High Molecular Weight Polyethylene (UHMWPE) Films

Recently, high thermally conductive polymers have emerged as low cost and energy efficient alternatives to traditional use of metals in heat transfer applications. Here, we present development of ultra-high molecular weight polyethylene (UHMWPE) thin films with high thermal conductivity. The fabrication platform is based on a sol-gel process followed by mechanical drawing. After gel formation and partial drying, UHMWPE films are mechanically stretched at elevated temperatures, resulting in macroscopic plastic deformation as well as additional polymer chain alignment and crystallization. Both the extrusion and stretching procedures have been automated, and custom software incorporates parameter "recipes" to allow selection of a range of desired process variables. Structural characterization (XRD, DSC, and SEM) of these films suggests highly aligned polymer chains and crystallinity greater than 99%. The Angstrom method is utilized to measure in-plane thermal conductivity of these films along the drawing direction.