Nonformaldehyde Durable Press Finishing of Cotton Fabrics by Combining Citric Acid with Polymers of Maleic Acid

Abstract

In our previous research, we investigated the use of two polymers of maleic acid, i.e., the homopolymer (PMA) and the terpolymer (TPMA), for crosslinking cotton cellulose. We found that PMA and TPMA were less effective than 1,2,3,4-butanetetracarboxylic acid (BTCA) due to the low mobility of the anhydride intermediates to access the cellulosic hydroxyl during a curing process. We found that the hydroxyl of citric acid (CA) hinders its esterification with cotton cellulose, and so is less effective than 1,2,3-propanetricar boxylic acid as a crosslinking agent for cotton. We also found that CA esterifies the anhydride intermediate of PMA or TPMA on the cotton fabric formed under curing con ditions. In this research, we observed a synergistic effect by combining PMA or TPMA with CA as co-crosslinking agents for cotton fabrics. The combination of TPMA/CA is more effective than the PMA/CA combination for imparting wrinkle resistance to the finished cotton fabrics. Cottons finished with the TPMA/CA combination show superior durable press performance, good laundering durability, and high fabric strength retention. The superior performance and cost effectiveness of this new finishing system makes it feasible as a replacement for formaldehyde-based durable press finishes.