A novel approach to excellent UV protecting cotton fabric with functionalized MWNT containing water vapor permeable PU coating

This research paper presented a novel approach of developing excellent protection from ultraviolet (UV) radiation of cotton fabrics by means of water vapor permeable (WVP) coatings containing multiwall carbon nanotube (MWNT), a stable and strongly UV absorbing species. The WVP of MWNT containing UV protective coatings of the present development are formed from solution polymer of hydrophilic polyurethane (HPU). MWNTs were dispersed in HPU solution by functionalization of MWNT. The nanotube containing HPU coating shows excellent protection against UV radiation, with only 1 wt % of MWNT (calculated based on solid content of the polymer), a UV Protection Factor (UPF) of 174 and with 2.5 wt % of MWNT a UPF of 421 was obtained, which stated excellent protection (UPF 50) according to the Australian/New Zealand standards. Scanning electron micrographs of coated fabrics surface showed a film like polymer coating, confirming the fabric surface was successfully coated by polyurethane. The coated fabrics would maintain very good water vapor permeability, hence confirmed the wearing comfort. Room temperature (20-23 degrees C) range soft segment crystal melting of HPU enhances the permeability of coated fabrics. (c) 2006 Wiley Periodicals, Inc.