Fabrication of 0.8BaTi4O9-0.2BaZn2Ti4O11 filled and glassfiber reinforced polytetrafluoroethylene composites with near-zero temperature coefficient of dielectric constant

Abstract

A study on 0.8BaTi4O9-0.2BaZn2Ti4O11 (BZT) filled and glassfiber (GF) reinforced polytetrafluoroethylene (PTFE) was described. The content of GF was 4 wt. %, and the BZT content varied from 26 wt. % to 66 wt. %. BZT complex phase powder was prepared by one synthetic route and modified using perfluorooctyltriethoxysilane (F8261). The microstructure, thermal properties, dielectric properties and temperature coefficient of dielectric constant of the composites were investigated in detail. The results revealed that BZT/GF/PTFE composites hold outstanding dielectric properties and stable thermal properties. Moreover, the specimens exhibited strong hydrophobicity due to the modification of filler using F8261. The BZT/GF filled PTFE composites exhibited reliable dielectric constant (εr = 4.4), acceptable dielectric loss (tan δ = 0.001), low water absorption (0.02%) and a near-zero temperature coefficient of dielectric constant (τε = 1.57 ppm/°C) at filler with contents of 4 wt. % GF and 46 wt. % BZT.