Effect of chelating polymer as chelating agent on the PZT/PVDF pyroelectric composites

Pyroelectric composites of PZT/PVDF with 0–3 connectivity were prepared by hot-pressing technology. In the composite systems, the ethylene diamine tetraacetic acid (EDTA) was used as a chelating agent to modify the surface combination between the polymer phase and the dispersed filler phase, and its effects on the microstructure, thermal properties, volume conductivity, dielectric properties and pyroelectric properties were investigated in detail. The scanning electron microscope micrographs showed that the interaction between PZT and PVDF could be effectively improved by introducing EDTA. The FTIR spectra analysis and DSC scans indicated that with the increasing of EDTA addition, the crystallization of PVDF was enhanced gradually accompany with the emergence of a small amount of β-PVDF phase. Owing to the enhancement of chelation bonding, the thermal properties and volume conductivity were both optimized, which meant the interfacial adhesion and charge transfer became more efficient. As a result, the pyroelectric properties of the composites were significantly improved. Especially, with 0.6 wt% EDTA addition, the pyroelectric coefficient was raised to be about 30 % higher than that of the untreated composites.