The smart control of cotton fabric comfort by cross-linking thermo-responsive random copolymer is investigated. The monomers 2-(2-methoxyethoxy) ethoxyethyl methacrylate (MEO2MA) and ethylene glycol methacrylate (EGMA) with a molar ratio of 17:3 are selected to synthesize the thermo-responsive random copolymer poly(2-(2-methoxyethoxy) ethoxyethyl methacrylate- co-ethylene glycol methacrylate), abbreviated as P(MEO2MA- co-EGMA). By using citric acid as a cross-linking agent, the obtained P(MEO2MA- co-EGMA) is successfully immobilized onto cotton fabrics. Smart control is achieved from the thermo-responsive behavior of the copolymer. Cross-linked P(MEO2MA- co-EGMA) will collapse when the ambient temperature exceeds its transition temperature. Therefore, the formerly compact P(MEO2MA- co-EGMA) layer will switch to a porous structure, and the air/moisture permeability of the textiles is enhanced. As the comfort of the textiles is closely related to the air/moisture permeability, a smart control of the cotton fabric comfort can be realized. In addition, the softness of cotton fabrics with and without thermo-responsive polymers does not show a prominent change, even when the applied solution concentration is as high as 16% (wt%). On the contrary, the stiffness of the cotton fabric coated with poly( N-isopropylacrylamide) (PNIPAM) is significantly higher than the original cotton fabric, indicating that homo PNIPAM is less suitable for textiles used in daily lives. Moreover, the whiteness and mechanical properties are studied and stay unchanged after cross-linking. As a consequence, the introduction of P(MEO2MA- co-EGMA) into textiles can provide textiles with smart control of cotton comfort, and it will not influence the wearabilities of the textiles.
Stimuli-responsive hydrogel consisting of hydrazide-functionalized poly(oligo(ethylene glycol)methacrylate) and dialdehyde cellulose nanocrystals
