Preparation of Waterproof and Breathable Polyurethane Fiber Membrane Modified by Fluorosilane-modified Silica

Polyurethane is a thermoplastic elastomer with excellent physical and chemical properties, the hydrophilicity of PU limits the wide application in the waterproof and breathable materials market. In this study, SiO2 nanoparticles were hydrophobically modified by fluorosilane to prepare the fluorosilane-modified silica (F-SiO2), then it was added into the synthesized polyurethane to prepare waterproof and breathable film (F-SiO2/PU) by electrospinning. Compared with polyurethane membranes, F-SiO2/PU composite membranes could form rough morphological surface through the blending of F-SiO2. The experimental results showed that the water contact angle of the composite nanofiber membranes increase with the addition of the amount of modified silica, and the water contact angle reached 135 o when the dosage of F-SiO2 was 5 wt%. The composite nanofiber membranes could be endowed with excellent waterproof performance, hydrophobicity (50 kPa) and moisture permeability (10.4 kg/m2•h). Besides, the prepared membrane can remain the hydrophobic property stability under the dynamic tensile of large-scale deformation.