Enhanced electrocaloric effect in poly(vinylidene fluoride-trifluoroethylene)-based terpolymer/copolymer blends

The electrocaloric effect in the blends of poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) with small amount of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) is investigated. It was found that small amount of P(VDF-TrFE) (similar to 10 wt. %) can cause a more than 10% increase in the crystallinity in the blends. Although the two polymers form separate crystalline phases, the interfacial couplings to the random defects in the terpolymer convert the normal ferroelectric P(VDF-TrFE) into a relaxor ferroelectric. As a result, the blends with 10 wt. % of P(VDF-TrFE) exhibit a 30% increase in the adiabatic temperature change over the entire experimental temperature range (20 degrees C-60 degrees C). (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4722932]