Study on Glass Fabric Reinforced Polytetrafluoroethylene Composites Infused with Melted Cyanate Ester Resin

Melted bisphenol A dicyanate ester (BADCy) resin was infused into glass fabric/ PTFE(GF/PTFE) wave-transparent composites to improve the mechanical properties of GF/PTFE composites. The influence of the infusing process, the porosity of GF/PTFE composites, and the content of infused BADCy resin on the dielectric and mechanical properties of GF/PTFE composites was studied. The fracture surfaces of the broken specimens were also examined by scanning electron microscopy (SEM). It was found that when the porosity of GF/PTFE composites was 25%, the infused temperature is 85°C, and the vacuum is 0.01 MPa, the infused contents of BADCy in GF/PTFE/BADCy composites could reach 14.4%. The tensile strength, flexural strength, and interlaminar shear strength (ILSS) of GF/PTFE composites were improved from 81.6, 64.4, and 4.8 MPa to 186.6, 163.5, and 26.2 MPa, respectively. At the same time, the dielectric constant (ε) and tangent dielectric loss angle (tan δ) of GF/PTFE composites increased slightly. The wet/hot and environment-resistant investigation showed that the GF/PTFE composites infused by BADCy resin possessed low water absorption, small coefficient of thermal expansion(CTE), and good anti-environment properties.