Preparation and Electromechanical Properties of PVDF Matrix Piezoelectric Composites Highly Oriented BaTiO_3 Whiskers

摘要

The piezoelectric composites containing highly oriented BaTiO_3 whiskers as active phase and PVDF as matrix have been prepared by micro-hole extrusion and orientation in carried fibers. The morphology of oriented BaTiO_3 whiskers and microstructure of the composites were observed by SEM, As for its electromechanical properties, it is found that the dielectric constant, piezoelectric constant and remnant of polarization in the BaTiO_3 whisker-PVDF composite are considerably higher than that in the BaTiO_3 powders-PVDF composite, while the loss factors follow the opposite trend. For the BaTiO_3 whisker-PVDF composite, the values of epsilon, d_(33) and P_r parallel to the whisker orientation (normal specimen) are much higher than that perpendicular to the whisker orientation (parallel specimen). The significant effects of the connective passages of active phase on electromechanical properties of the piezoelectric composites has also been investigated.