Shape memory and breathable waterproof properties of polyurethane nanowebs

An intelligent textile with optimal environmental responses was developed from electrospun nanowebs with controllable pore structures via the spinning conditions. The use of shape memory polyurethane allowed the material’s shape to be retained and recovered through heating. The thickness of the electrospun nanoweb was varied so as to manufacture the membrane with various pore diameters. The samples were evaluated for shape memory performance, air and water vapor permeability. All samples showed shape recoveries of at least 99% and shape retentions of at least 94%. Increasing the thickness, increased the shape retention but slightly reduced the shape recovery. Pore size decreased with increasing thickness, thus decreasing air and water vapor permeability. Stretched nanowebs showed the greatest differences in water vapor permeability at 10°C with 90% RH and at 15°C with 90% RH compared with original nanowebs.