A study of thermosensitive poly(N-isopropylacrylamide)/polyurethane hydrogel modified nonwoven fabrics

A novel smart textile, which has great merits such as nutrient controlled release and antibacterial activities, has been developed and tested systematically. To achieve the smart textile, nonwoven fabric was modified by the thermosensitive PNIPAAm/PU hydrogels and then modified by chitosan, which endow the modified nonwoven with antibacterial activities. Temperature sensitivity, thermo property, controlled release and antibacterial activity of the novel fabrics were also investigated systematically.; The percentage of grafted hydrogels is greatly dependent on the monomer concentration. Two modifying mechanisms may exist during the process of modification. One is the free radical graft copolymerization of NIPAAm and PU with polysaccharide initiated by APS. Another mechanism involved might be physical entrapment and anchoring.; The DSC results suggested that the phase transition temperature of the smart fabrics obtained is between 32°C and 35°C, which is very close to the lower critical solution temperature (LCST) of the pure PNIPAAm hydrogel. With the support of nonwoven fabrics, the PNIPAAm/PU hydrogel has a good mechanical performance.; After chitosan modification, the thermosensitive hydrogel modified nonwoven has antibacterial activity to S. aureus and E. coli . The antibacterial efficiency is near 80% tested by using shaking flask method. The novel textile is still temperature-sensitive after chitosan modification.; Vitamin C (Vc) was used as model nutrient to study the release behaviors of the smart fabrics. All the releasing processes are biphasic. The first stage is short but the releasing speed is fast. The second stage is relatively stable. The release behavior of Vc from the PNIPAAm/PU hydrogels modified fabrics can be affected by temperature. Moreover, after chitosan modification, the releasing mode has little significant changes.; With temperature controlled release property and antibacterial activity, the novel smart fabric can be served as both medical and cosmetics material with great potential.