The influence of silica aerogels on physical, mechanical, and morphological properties of melt-spun POY and DTY polyester yarns

Thanks to over 90 vol% air content, aerogels are the lightest known solid state materials with low thermal conductivity and high surface area. Aerogels are also suitable candidates in fibrous blankets, construction, and thermoset composites, while their fragile characteristic limits their application in thermoplastic composites so far. In this study, silica aerogel-filled polyester nanocomposite filaments were produced through high-speed melt-spinning after twin-screw extrusion of their nanocomposite compounds, containing 0.4, 1, 2 and 4 wt% filler contents. This approach is a solution for overcoming to the dusting problems in aerogel/fiber blankets, aiming in insulation or other application perspectives. The compounding and melt-spinning trials resulted in successful fiber production (except for 4 wt% filler content). Microscopic observations showed a solid cross-section for the fibers (24 μm in diameter) while the aerogels caused a rough surface for the nanocomposite fibers along with hydrophobic characteristic (high contact angle). BET analysis showed 90% porosity for as received aerogels and 63% for the aerogels after processing with polymer. In the same line, densitometry confirmed the partial porosity of the aerogels in masterbatches and nanocomposite fibers. Mechanical characterizations showed that the fibers have acceptable performance after the spinning process. Thermal analysis results confirmed the presence of aerogels within the fibers. These developed nanocomposite fibers are suggested for future evaluations to be considered in different applications.