Fabrication of 0.8BaTi(4)O(9)-0.2BaZn(2)Ti(4)O(11) filled and glassfiber reinforced polytetrafluoroethylene composites with near-zero temperature coefficient of dielectric constant

A study on 0.8BaTi(4)O(9)-0.2BaZn(2)Ti(4)O(11) (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 per-fluorooctyltriethoxysilane (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 (epsilon(r) = 4.4), acceptable dielectric loss (tan delta = 0.001), low water absorption (0.02%) and a near-zero temperature coefficient of dielectric constant (T-epsilon = 1.57 ppm/degrees C) at filler with contents of 4 wt. % GF and 46 wt. % BZT. (C) 2018 Elsevier B.V. All rights reserved.