Waterproof and Moisture permeable Nanofibrous Membranes with Cross-Linked Structure

Abstract

Functional flexible membranes with superior water repellency and moisture permeability, which prevent water penetration and allow rapid passage of water vapor, offer new possibilities for a wide range of applications in various fields. A new type of functional nano-fiber membrane can be prepared by a facile electrospinning method, thermal post-treatment and chemical crosslinking, which can provide excellent mechanical properties. In this study, low melting point polyvinyl-butyral (PVB) elastomers were incorporated into polyvinylidene fluoride (PVDF) to change the adhesion between the membrane bonding network structure and the fibers to impart durable and strong mechanical properties to the membrane. The effects of PVDF/PVB concentration on the waterproof and breathable properties were investigated by systematically tabulating the morphology, contact angle, water vapor transmission rate (WVTR), and fracture length of PVDF/PVB. The results showed that the prepared nanofiber membrane could maintain high hydrostatic pressure (85.15 kPa) and high water vapor transmission rate (10.28 kg m-2d-1), and at the same time, the membrane exhibited excellent tensile stress (13.07 MPa), indicating its wide application in separation process and protective clothing.