Easy care of silk fabrics realized by crosslinking thermo-responsive copolymer film on its surface

An easy care of silk fabrics is realized by crosslinking a thermo-responsive copolymer film onto its surface. The thermo-responsive copolymer poly(N-isopropylacrylamide-co-oligo[ethylene glycol] methyl ether methacrylate-co-ethylene glycol methacrylate), abbreviated as P(NM-co-OA₃₀₀-co-EA₃₆₀), is synthesized by sequential atom transfer radical polymerization. By applying 1,2,3,4-butanetetracarboxylic acid as crosslinker, the thermo-responsive P(NM-co-OA₃₀₀-co-EA₃₆₀) film can be immobilized onto the silk fabrics. The transition temperature (TT) of the P(NM-co-OA₃₀₀-co-EA₃₆₀) film crosslinked on silk fabrics is around 46 °C. The reversible transition behavior can effectively reduce the attachment between lipophilic stains and P(NM-co-OA₃₀₀-co-EA₃₆₀) film, inducing a high efficiency of stain removal. Simply rinsing with deionized water at 25 °C (below its TT) for 30 s, 60% of stains can be removed. Moreover, the crosslinked P(NM-co-OA₃₀₀-co-EA₃₆₀) film turns hydrophobic during outdoor activities or drying. Thus, the repelled water molecules can be easily evaporated from the silk fabrics and the drying process is 25% faster than that without crosslinked P(NM-co-OA₃₀₀-co-EA₃₆₀) film. Based on the excellent performance of stain removal and quick drying, the silk fabrics crosslinked with thermo-responsive copolymer film can be broadly used to design silk-based costumes for daily use.