Preparation and properties of polymer matrix piezoelectric composites containing aligned BaTiO3 whiskers

A piezoelectric composite has been prepared with highly aligned BaTiO3 whiskers as the active phase and polyvinylidene fluoride (PVDF) as the matrix. Its dielectric and electromechanical properties are characterized. It is found that the dielectric constant (e), piezoelectric constant (d33) and remnant polarization (Pr) are considerably higher in the whisker composite than in the corresponding composite containing BaTiO3 powders as the active phase, while the loss factors follow the opposite trend. For the whisker composite, e, d33 and Pr along the direction of the whisker orientation are much higher than the values normal to the whisker orientation. The reasons for the observed differences are discussed.