Segmented shape memory polyurethane and its water vapor transport properties

An attempt has been made to review the influences of different structural factors on physical and water vapor transport properties of segmented shape memory polyurethane (SPU) for breathable textile, biomedical and many other industrial applications. The differences between ordinary, segmented and segmented shape memory polyurethanes have been reviewed. The principle of temperature-sensitive SPU has been stated. Water vapor transport through dense segmented polyurethane is a collective process of diffusion and sorption and, hence, the permeability of mass molecules through dense membrane depends on both diffusion and sorption. Therefore, the study of different structural factors on water vapor transport properties are important, in order to enhance the permeability of non-porous membranes. The effects of different structural factors, viz., hard and soft segment, functional groups, hydrophilic groups, crystallites and additives on permeability have also been included in this review article.