Thermal properties and physiological responses of vapor-permeable water-repellent fabrics treated with microcapsule-containing PCMs

The purpose of this study is to develop a thermally adaptable, vapor-permeable water-repellent fabric. Vapor-permeable water-repellent fabrics with and without octadecane-containing microcapsules are obtained by a wet porous coating process. The thermal and physical properties of the octadecane-containing water-repellent fabrics (WR-PCM) are compared with the water-repellent fabric without octadecane (WR). The heat of fusion (DeltaH(f)) of WR-PCM is 13.50 J/g at 29.06degreesC, and the heat of crystallization (DeltaH(f)) is 14.02 J/g at 11.45degreesC. The thermal properties remain relatively high after thirty launderings. WR-PCM shows a lower water vapor transmission value than WR and a lower air permeability. The water repellency of both fabrics is 100%, but the water resistance of WR-PCM decreases dramatically. In wear trials, the mean skin temperature and microclimate temperature of subjects wearing active wear made with WR-PCM are lower than those made with WR. But the microclimate humidity with WR-PCM has a higher rate than WR. Although the subjective sensations of WR and WR-PCM are not significantly different, WR-PCM is cooler and more comfortable than WR. The results of this study indicate that octadecane-containing microcapsules in water-repellent fabrics provide a cooling effect but sacrifice water resistance.