Design and Fabrication of Flexible Poly(Vinyl Chloride) Dielectric Composite Reinforced with ZnO Microvaristors

Abstract

Flexible poly(vinyl chloride)/varistor composites were fabricated by solution casting method. High-field ZnO varistor particles processed from micron-sized Zn dust is explored as multifunctional filler for PVC composites. Mechanical blending of Zn dust with La2O3-CeO2 rare earths and varistor forming minor additives followed by sintering at 1250 8C resulted in fine-grained ZnO varistors. Bulk varistor was subsequently milled to obtain ZnO microvaristor grains. The effect of microvaristor on the UV stability, dielectric, and mechanical properties of the PVC composite was analyzed. The varistor filler in PVC enhanced the microhardness and retained the tensile properties without any significant loss. After UV irradiation PVC/varistor composite shows remarkable mechanical stability retention (95%) compared to pure PVC (75%). Also, microvaristor reinforcement resulted in dielectric constant tunability (E52–37) without any drastic change in the dielectric loss (0.02–0.05). Thus, Zn dust-derived ZnO varistors could be potentially exploited to design functional PVC composites for electronic applications.