Waterproof and Moisture Permeable Nanofibrous Membranes with Multi-scale Cross-Linked Structure

Abstract

Preventing the penetration of water while allowing it to pass through quickly is the key to achieving waterproof and breathable membranes; it opens up new possibilities for applications in all areas. Herein a novel functional nanofibrous membrane can be prepared via a facile electrospinning strategy, thermal post-treatment and chemical cross-linking, capable of providing excellent mechanical performance. Low-melting-point polyvinyl butyral (PVB) elastomer are added to polyvinylidene fluoride (PVDF) to modify the bonding network structure of the interfiber-adherent membrane, imparting durability and high mechanical properties to the membrane. Subsequently, the blocked isocyanate prepolymer (BIP) is used as the chemical cross-linker with PVDF and polyvinyl butyral (PVB) hybrid system to strengthen the cross-linking structure. Through systematically characterize the morphologies, contact angle, water vapor transmittance rate (WVTR) and hydrostatic pressure, it is studied that the effect of concentrate of PVDF/PVB/BIP and thermal-induced temperature on the waterproofness and breathability. The results indicate that the prepared nanofibrous membranes can maintain highly hydrostatic pressure (93.27kPa) and high WVTR (10.28 kg m−2 d−1); meanwhile, the membranes exhibit the excellent tensile stress (13.07MPa), indicating that it has a broad potential application prospect in the separation process and protective clothing.

Keywords

• polyvinylidene-fluoride
• waterproof and moisture permeable
• microporous membrane
• electrospinning
• multi-scale cross-linked