Effects of CaTiO3 Loading on the Properties of PTFE/TiO2 Composites

Abstract

In this paper, a detailed study was carried out on the PTFE reinforced with TiO 2 and CaTiO 3 . The filler content of ceramic powder was a fixed value of 61 wt% and the content of CaTiO 3 in PTFE matrix varied from 0 wt% to 16 wt% with a step size of 4 wt%. The effects of CaTiO 3 loading on the density, moisture absorption, thermal expansion, microstructure and microwave dielectric properties were investigated. As CaTiO 3 loading content increased from 0 wt% to 16 wt%, the thermal expansion initially displayed a sharp increase, and showed a slight enhancement when the content of CaTiO 3 exceeded 12 wt%. The density experienced a continuous decrease with the addition of CaTiO 3 . The moisture absorption displayed a steady increase with the increasing Ca-TiO 3 loading amount. The changing of dielectric constant (εr) and loss tangent (tanδ) were similar to that of the moisture absorption in a manner. Good dielectric properties with values of εr = 11.60, tanδ = 0.002 were obtained in the PTFE matrix with 16 wt% CaTiO 3 and 45 wt% TiO 2 .