Application of polycarboxylic acids to cotton fabrics under mild curing conditions

Cellulosic materials are treated with non-formaldehyde durable press finishing agents based on polycarboxylic acids (PCA) such as 1,2,3,4-butanetetracarboxylic acid (BTCA) or citric acid (CA) in combination with sodium hypophosphite (SHP), as an appropriate catalyst, at 180 degrees C for 90 sec. CA decomposes over 153 degrees C, forming by-products that cause yellowing of the finished fabric. The present study investigates the curing process under mild conditions. The textile physical properties of the BTCA and CA treated cotton fabrics were evaluated in terms of dry crease wrinkle recovery (DCRA) and whiteness index (WI). In addition, the fabrics were tested by FT-IR/ATR. The amount of cotton-bound PCA was determined by isocratic HPLC. The results obtained make evident that, below 150 degrees C, no unsaturated PCA are produced, and also that the treatment of PCA finished cotton fabrics with TEOS/GPTMS solutions (tetraethoxysilane/3-glycidyloxypropyltrimethoxysilane) improves the DCRA values.