Durable Polyurethane/SiO₂ Nanofibrous Membranes by Electrospinning for Waterproof and Breathable Textiles

Recently, waterproof and breathable materials have attracted extensive attention and have been used in a broad range of applications such as clothing, sports equipment, medical hygiene products, and other fields. In this study, an efficient chemical modification method was suggested to prepare polyurethane/SiO2 nanofibrous membranes with superhydrophobicity and durability. A polyurethane emulsion was treated with 4,4′-methylenebis(phenyl isocyanate) and 3-aminopropyltriethoxysilane. This emulsion process was combined with the emulsion electrospinning technique and a hydrothermal-assisted sol–gel process to prepare superhydrophobic polyurethane nanofibrous membranes. The final polyurethane/SiO2 nanofibrous membranes exhibited a hydrostatic pressure of 8.02 kPa, an air permeability of 3.89 mms–1, and a water vapor transmission rate of 10.12 kg m–2 d–1. Results also showed that the water contact angle of the nanofibrous membranes reached 154°, and the stress and strain were 5.3 MPa and 198%, respectively. In addition, the adhesion between SiO2 and the PU nanofibrous membranes was high, and the weight loss rate of SiO2 remained at approximately 9.72% after the ultrasonic cleaning time exceeded 24 h. These results suggested that the PU/SiO2 nanofibrous membranes were expected to provide a new perspective for waterproofing and moisture permeability.