A phase change material embedded composite consisting of kapok and hollow PET fibers for dynamic thermal comfort regulation

Kapok fiber, an agricultural product, is a typical cellulosic fiber with the features of thin cell wall and large lumen. Herein, a microtubule-based composite with high porosity of 98.03 % was prepared using kapok fibers and hollow PET. The kapok fiber-based composite successfully encapsulated a phase change material (PCM), that is a fatty acid ester of myristic acid and tetradecyl alcohol (MA-TD), in the microtubules by vacuum impregnation. The SEM showed that the PCM was encapsulated in the lumens of the fibers with a calculated percentage of 40.5 %. This condition provided the composite a basic thermal insulation from air pockets in the composite and a dynamic thermal insulation from the PCM. The kapok/PET/MA-TD could absorb 76.8 J/g latent heat in the comfort temperature range of 24 degrees C - 42.3 degrees C or release 77.4 J/g latent heat in the comfort temperature range of 29.7 degrees C - 10.5 degrees C. It withstood repeated laundry and exhibited robust leakage resistance to continuous heating/cooling under pressure. In addition, the composite was successfully used to dynamically regulate the temperature with obvious thermal regulating capacity in the simulated cooling/hot environments. Such material will be a robust candidate for dynamic heat regulating and thermal insulating applications.