The Combination of Itaconic Acid and Sodium Hypophosphite as a New Cross-Linking System for Cotton

In this research, we studied cross-linking of cotton fabrics using the combination of itaconic acid (ITA) and sodium hypophosphite (NaH2PO2). ITA, a bifunctional carboxylic acid, was able to esterify cotton cellulose to form a single ester linkage, but it was not able to form cross-linking between two cellulose molecules. In the presence of NaH2PO2, the amount of ester formed on cotton fabric was increased substantially and the esterification temperature of ITA was reduced. Therefore, NaH2PO2 functioned as a catalyst for esterification of cotton by ITA. Moreover, we found that wrinkle resistance of the cotton fabric was significantly improved when cotton fabrics were treated with the combination of ITA and NaH2PO2.We also found that phosphorus was bound to the treated cotton fabric and that the increase in the wrinkle recovery angle of the treated fabric was correlated to the increase in the amount of phosphorus bound to cotton. All the data indicated that H-P-H of sodium hypophosphite probably reacts with the >C=C< of two ITA molecules, which are also esterified with cellulose, thus forming a cross-linkage between the two cellulose molecules. The cotton fabrics treated with the ITA/NaH2PO2 system demonstrated a high level of durable press performance with significantly lower tensile strength loss than those treated with the formaldehydebased dimethyloldihydroxyethyleneurea.