Nondestructive Recovery of Cotton from Waste Polycotton Textiles by Catalytic Hydrolysis

Abstract

Cotton is the most important natural fiber for the textile industry, and its production relies on water- and pesticide-intensive cultivation. Recycling cotton from waste textiles represents an important way to close the loop of the circular economy, but it usually leads to cotton degradation due to the harsh recycling conditions used. Here, we report an approach for rapid and nondestructive recovery of cotton from polyester-cotton blended fabrics via mild alkaline hydrolysis catalyzed by a binuclear zinc catalyst. Through this method, the separation efficiency of polycotton textiles exhibits a 7-fold improvement relative to noncatalytic alkaline hydrolysis, with cotton recovery rate up to 97.5%. Meanwhile, the degree of polymerization and the crystalline structure of the recycled cotton are almost identical to that of the raw material, which is difficult to achieve under previously demanding conditions. Moreover, we demonstrate that this approach can process a wide range of real-world polycotton textiles with different colors and compositions. This rapid and closed-loop cotton-to-cotton recycling could bring great economic value to the textile recycling industry and would significantly reduce the consumption of fresh water and pesticides in cotton cultivation.