Effect of liquid ammonia and protease on surface modification and shrink resistance of wool

In order to improve the surface properties of wool fiber, the wool fabric was treated with liquid ammonia and protease treatments successively. The results showed that liquid ammonia pretreatment could cause certain damage to the surface structure and disulfide bonds in keratin, which enhanced the action of protease on wool surface and catalytic hydrolysis of the cuticle. The joint treatment of liquid ammonia and protease changed the secondary structure of wool. The content of α‐helix and random crimp increased, while the content of β‐sheet decreased. In addition, the shrink resistance of wool fabric was significantly improved without obvious losses in tensile strength and elongation. The combination of liquid ammonia and protease treatments provides a potential new method for the surface modification and eco‐friendly shrink‐resistant finishing of wool and further widens the application of liquid ammonia in textile industry.