NIPAM polymer/polyurethane resin films and the moisture transport characteristics of film-treated fabrics

Numerous studies have addressed the use of poly(N-isopropylacrylamide) or (poly-NIPAM) homopolymers in drug delivery systems. However, their application has not been extended to textiles owing to their high solubility in water. In this study, we investigated thermo-responsive, hydrophilic, breathable, waterproof films as well as fabrics treated with these films. To impart temperature-sensitivity, a poly-NIPAM polymer was used, with water solubility at or below the lower critical solution temperature (LCST). The poly-NIPAM used in this study had to be insoluble in water, even at the LCST or below it. Consequently, this study was performed using films wherein poly-NIPAM was copolymerized with hydrophilic polyurethane (PU). The change in water solubility of the homopolymer at temperatures greater than or less than the LCST could be verified from the water absorption coefficient of the films observed at various temperatures. Subsequently, we ascertained the functionality of the temperature-sensitive water absorption feature. In addition, we validated the functionality of the breathable, waterproof films and the condensation-inhibition capacity of film-treated fabrics. As a result, we postulated that the fabrics coated with poly-NIPAM/PU copolymer films could serve as functional materials for apparel with novel and improved moisture transport characteristics.