[摘要]：The role of the sample crystallinity on the electrocaloric effect (ECE) of ferroelectric polymers was investigated in miscible blends of poly(vinylidene fluoride-trifluoroethylene) and poly(methyl methacrylate). Polarization switching measurements gave the electric field required to realize full dipole realignment. Conformational entropy and temperature changes were obtained from the thermal dependence of the dielectric permittivity in the paraelectric phase. The obtained ECE values were relatively high: they reached 18.6 J/kgK and 4.7 K for the pure copolymer and decreased ca. 74% for a 70% crystallinity decreasing. The sample crystallinity appears clearly as a key parameter controlling the ECE in non-oriented ferroelectric polymers. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3702781] |
