Thermoresponsive smart textile

Abstract

The developments in temperature-sensitive copolymers have been reviewed critically and an attempt has been made to synthesize a series of temperature-sensitive random linear and crosslinked copolymers of <i>N</i>-tert-butyl acrylamide (NTBA) and acrylamide (Am) in varying proportion from 80:20 mol % to 20:80 mol % with transition temperature varying between

2°C and 58°C. Linear copolymer with 40:60 feed ratio of NTBA and Am with actual incorporation of NTBA to the extent of 27 mol% was processed into mechanically strong films of 10-200 μm thickness. The transition temperatures of the crosslinked films are found to shift towards the lower temperature from 37°C (in linear copolymer) to ~ 22-25°C. In thin

films of 10 μm, the swelling percentage increases to 4200 and the response time reduces to 5 min from 680% and 120 min respectively of the polymerized gel samples (2 mm disc) of the same composition. Reversible transition was also observed over repeated cycling. These copolymers were chemically integrated to the textile substrates for developing smart textile

materials. Cotton yarns coated with this copolymer show a broad transition in the temperature range 15-30°C, and an equilibrium volumetric swelling of ~ 4500% in about 5 min and deswelling within 10 s. A model fabric, fabricated using the coated cotton yarns, exhibited temperature-responsive percentage cover (100% at 6°C and 43% above transition temperature).