Structural Tailing and Pyroelectric Energy Harvesting of P(VDF-TrFE) and P(VDF-TrFE-CTFE) Ferroelectric Polymer Blends.

ABSTRACT

The copolymer P(VDF-TrFE) is a normal ferroelectric because the bulky TrFE monomer improves its crystalline chain structure, while the terpolymer P(VDF-TrFE-CTFE) is a relaxor ferroelectric because the third monomer CTFE makes it amorphous. Herein, in order to induce a crystalline beta phase in the terpolymer, we blended a small amount of crystalline P(VDF-TrFE) into P(VDF-TrFE-CTFE) and investigated the effect of blending on the pyroelectric energy harvesting (PyEH) properties. The polarization-electric field hysteresis loops at different temperatures and energy densities were investigated. The PyEH energy density (N D) is compared with the electrical energy density (U E). The U E and N D at the ferroelectric-paraelectric transition temperature for the χ = 0.1 blend are reported as 3.18 and 5.04 J/cm3, respectively, which are higher than the other polymer blends. Interestingly, the N D of the χ = 0.9 blend is found to be 3.44 J/cm3 when operated at lower and higher temperatures, that is, at T L = 25 °C and T H = 40 °C, respectively, which is the highest possible energy density at the lowest possible transition temperature for the polymer blends.