Effects of Size of Spray-Dried PZT Powder and Dipole Density of Polymer Matrix on the Electrical Properties of PZT/Odd-Odd Nylons 0-3 Composites

A series of 0-3 composites of lead zirconate titanate (PZT)/ferroelectric odd-odd nylons was prepared with variations in the size of PZT powder and in the dipole density of ferroelectric odd-odd nylons. The as-formed PZT powder prepared by a spray-drying technique consists of spherical granules composed of large numbers of interconnected fine particles. Electrical properties of the composites as a function of the size of this particular PZT powder and the dipole density of ferroelectric odd-odd nylons were studied. With the PZT powder sintered at 1100 degrees C, the relative permittivity, polarization, and piezoelectric strain coefficient (d(33)) of the PZT/nylon composites increased with increasing powder size of PZT. The electrical properties of the composites also increased as the dipole density of the polymer increased. The PZT/nylon 57 composite exhibited a high-relative permittivity and piezoelectric strain coefficient d(33) due to an increase in its dipole density. The optimum relative permittivity and polarization of this composite were obtained by the PZT with an average granule size of 95 mu m. The highest piezoelectric strain coefficient d(33) of the 0-3 composite was found at 28 pC/N whereas the relative permittivity was approximately 73.