Thermally Induced Chain Orientation for Improved Thermal Conductivity of P(VDF-TrFE) Thin Films

The potential for polymer thin films to be used as coatings or dielectrics is limited by their low thermal conductivity, κ. However, there have been very limited studies on κ enhancement for polymer thin films. In this work, we show that the out-of-plane κ of a poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) thin film can be enhanced when it undergoes the appropriate thermal annealing conditions. When the film is annealed above its melting temperature, we achieve a 300-400% increase in κ across the measured temperature range, compared to the as-cast film. We attribute this enhancement to the extensive ordering of polymer backbone chains perpendicular to the substrate during the melt-recrystallization process.