Jin-lian
Hong Kong Polytechnic University, Hong Kong
Title: Self-adaptive polymeric membrane with adjustable water vapor permeability
Biography
Biography: Jin-lian
Abstract
Many natural materials demonstrate adaptive abilities to keenly respond upon triggering of a suitable external stimulus. Nowadays, self-adaptive breathable polymeric membrane (SBPM) is becoming a fundamental material in various advanced applications such as protective garments/shoes, chemical/medical equipment, sophisticated electronics, and construction materials. SMPM usually introduces in the garment for the enhancing the comfort to the wearer body in extreme environmental conditions. In this context, a series of segmented shape memory polyurethanes (SMPU) was synthesis by adjusting the molecular weight of macroglycol, hard to soft ratio, and incorporation of carbon dot (highly oxygenating groups containing nanoparticles) in different weight % to obtain the suitable SBPM. SMPU showed good self-adaptive WVP by changing the free volume in their soft-segments upon triggering of a stimulus, especially heat. It is found that the mobility of soft segment is low below its transition temperature (Ttrans) and SMPU acts as an insulator. It helps to maintain the warmth and moisten skin along with a low WVP. When the used temperature is above the Ttrans, the soft segment of SMPU converts ‘active’ and increase the free volume in SMPU. This aids the transportation of more water vapor to retain the body dry and comfortable. The moisture level is also a very crucial factor which governs the comfort of clothing in addition to heat, as people can sweat both in high and low temperatures during a high degree of workload. The outcome polymeric membrane showed strong potential for textiles and packaging industrials, especially for sports wears, wound dressing and food storage, where moderate RH range is essential for human health.