Polyurethane-aerogel incorporated coating on cotton fabric for chemical protection

Abstract

This research aims to create a coated surface by integrating porous silica aerogel particles with polyurethane (PU) binder having simultaneous thermal comfort and protective performance. A surface layer on cotton fabric was developed by coating the fabric with PU and aerogel particles to protect against penetration of water and certain chemicals. Infrared spectroscopy characterisation of coated specimens revealed a stable coating on the fabric surface due to interfacial adhesion between cotton fibre and PU binder. The surface morphology of dispersed aerogel particles in the coating was analysed through scanning electron microscopy. Protective performance, including surface wettability and chemical resistance properties of coated fabrics, was assessed by measuring the water contact angle, water repellency rating and resistance to chemical penetration. The results showed that contact angles formed on PU–aerogel coated fabrics were similar to PU coated fabrics. The PU-aerogel coated fabrics, however, exhibited a higher water repellency rating due to increased hydrophobicity. Similar chemical resistance properties, with no decline in protective performance, were observed after the integration of porous aerogel particles. However, instead of liquid repellency resembling a PU coating, most of the chemicals were adsorbed in the aerogel coating. In the case of clothing comfort, no significant change of resistance to dry heat transfer was observed for the fabrics coated with aerogel particles. Moreover, a gradual improvement of moisture vapour transfer and air permeability with higher aerogel particle concentration led to improved perspiration transmittance that conferred better thermal comfort. The unchanged moisture management profiles of coated specimens, after incorporating aerogel particles, indicated that moisture vapour was diffused through uncovered aerogel pores. Integration of silica aerogel with PU binder in the coating on cotton fabric is a promising approach to developing protective clothing that will provide chemical protection as well as thermal comfort to the wearer.