Eco-friendly Shrink-Resist Finishing of Wool Through the Synergistic Effect of a Disulfide Bond Reducing Agent, Polydopamine, and Alkaline Protease

Abstract

In this study, dopamine was used in conjunction with protease to dynamically modify protease by the C–N bond. This combined operation is intended to prevent the hydrolysis of the wool scale in the process of modification, while the self-polymerization of dopamine in a pot allows it to be absorbed on the surface of the fiber, so that the effect of the protease on the wool scale is limited. In addition, the application of L-cysteine and Na₂SO₃ to restore the wool fiber pretreatment, by restoring the sulfur dioxide in the wool to reduce the structural integrity of the wool scales, improves the hydrolysis effect of protease on the wool scales while also allowing dopamine to be modified on the surface of wool fibers through C–S and C–N bonds. The combination of L-cysteine 2.5 g/L, protease 2.5 g/L, and dopamine 0.84 g/L gives the wool fabric felting a shrinkage of 6.64% and a strength loss of 5.7%. Compared to the pretreatment method of Na₂SO₃ restoration, the damage strength of wool fabrics has been greatly reduced. This synergistic treatment method provides a new idea for the shrinkage resistance of wool and expands the application of biotechnology-combined polymer technology in the wool industry.