Evaluation of ultimate engineering properties of polytetrafluoroethylene/carbon-aerogel/glass fiber porous composite

Abstract

A novel polytetrafluoroethylene (PTFE)/ carbon-aerogel (CA) coating was applied on the glass fiber mat (GFM) via a dip-coating procedure followed by a pad-dry-cure method. Dispersions and distribution of CA, fiber diameter, and surface roughness were assessed through scanning electron microscopy (SEM) and Atomic force microscopy (AFM). The effect of different coating baths — 50 and 100 g/L PTFE with various CA concentrations (0–6 W/V.%) — on thermal, electrical, mechanical, acoustical, permeability, and surface properties of the CA/PTFE/GFM composites was studied. Thermal and electrical properties revealed that porous carbonic fillers could improve thermal insulation and enhance electrical conductivity illustrating carbon-aerogel materials' notable property. After coating procedure, tensile strength increased from 1.06 MPa for neat GFM to 1.62 and 1.63 MPa for CA6/PTFE50/GFM and CA6/PTFE100/GFM, respectively, due to reducing fibers' surface defects and well-diffused PTFE polymer chains within the CA networks that generates strong interfacial interaction. In addition, air permeability and noise absorption coefficient decreased via raising the CA content due to enhancing the thickness and attenuating the received sounds through porous CA. Eventually, contact angle and sliding angle illustrated that the hydrophobicity increased by adding CA and PTFE due to reducing surface tension of the composites.