One-step fabrication of strengthened breathable composite nanofiber membranes by electrospinning/electrospraying for highly waterproof application

Waterproof breathable membranes (WBMs) have attracted intense research interest due to their wide applications, however, there are still great challenges in effectively preparing WBMs with desirable waterproofness, breathability and elasticity. Here, a facile and scalable fabricating strategy combining electrospinning and electrospraying is proposed to manufacture nanofiber WBMs, which are comprised of both hydrophobic thermoplastic polyurethane (TPU) nanofibers and inter-fiber polyvinyl butyral (PVB) bonding containing a short perfluoroalkyl hydrophobic agent. The obtained composite nanofiber membranes showed durable water/oil repellent properties against ultrasonic washing and abrasion. The interconnected fibrous structure together with liquid repellent surface have endowed the WBMs with comprehensive properties with hydrostatic pressure of 73.7 kPa, water vapor transmission rate of 6.88 kg m−2 d−1, outstanding tensile strength of 25.72 MPa and large elongation at break of 217%, which have exceeded the majority of their nanofiber counterparts. This work could provide a novel approach for the preparation of waterproof and breathable membranes with balanced structural stability, waterproofness and wearing comfort, especially suitable for the personal protective material application.