Thermal inter-fiber adhesion of the polyacrylonitrile/fluorinated polyurethane nanofibrous membranes with enhanced waterproof-breathable performance

Abstract

Abstract Macroporous membranes with robust waterproofness, breathability and mechanical properties have attracted a great deal of attention. However, great challenges still remained in developing an effective and cost-efficient method to fabricate such materials. In this study, polyacrylonitrile (PAN)/fluorinated polyurethane (FPU) nanofibrous composite membranes with enhanced waterproof and breathable performance were fabricated by combination of electrospinning and heat post-treatment. The introduction of FPU enriched the nanofibrous membranes with superhydrophobic surface with water contact angle of 151°, optimized pore size and porosity. Moreover, the relationship among hydrostatic pressure, pore structure and surface wettability has proven to be in accordance with Young–Laplace equation. By employing the heat post-treatment, the pristine PAN/FPU composite membranes were endowed with physically adhesion structure, thereby significantly improved the waterproof-breathable performance as well as the mechanical property. Owing to these effects, the resulting thermal treated PAN/FPU composite membranes exhibited the integrated properties of high hydrostatic pressure (114.6 kPa), water vapor transmission rate (10.1 kg m −2 d −1 ) and good tensile strength (9.4 MPa). Furthermore, the reinforced PAN/FPU nanofibrous composite membranes have great potential to be used as functional materials for fabricating separation media, filter, outdoor sportswear, chemical protective clothing, and army combat uniforms.