In this research, we studied cross-linking of cotton fabrics using the combination of itaconic acid (ITA) and sodium hypophosphite (NaH 2 PO 2 ). 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 NaH 2 PO 2 , the amount of ester formed on cotton fabric was increased substantially and the esterification temperature of ITA was reduced. Therefore, NaH 2 PO 2 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 NaH 2 PO 2 .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/NaH 2 PO 2 system demonstrated a high level of durable press performance with significantly lower tensile strength loss than those treated with the formaldehydebased dimethyloldihydroxyethyleneurea.

Polycarboxylic acids have been used as crosslinking agents for cotton fabrics and paper to replace the traditional formaldehyde-based reagents. Previously, we found that a polycarboxylic acid esterifies cotton cellulose through the formation of a five-membered cyclic anhydride intermediate. Both maleic acid (MA) and itaconic acid (ITA) are extremely difficult to polymerize under conditions normally used for free radical polymerization. It has been reported in the literature that treatment of cotton fabric with a mixture of MA and ITA significantly improved wrinkle-resistance of the fabric. In this research, we investigated the in situ copolymerization of MA and ITA on cotton fabric. Fourier transform-infrared spectroscopy was used to study the anhydride carbonyl formed on the cotton fabric treated with the mixtures of MA and ITA. A redox titration technique also was applied to determine the quantity of alkene double bonds on the treated fabric. It was found that free radical copolymerization of MA and ITA does not occur on the fabric at elevated temperatures when potassium persulfate is present as an initiator. It does occur, however, when both potassium persulfate and sodium hypophosphite are present on the fabric. The in situ copolymerization on the cotton fabric probably is initiated by a reduction-oxidation system.