Catalysis of the Cellulose-Cyclic Urea Reactions by Built-in Acid Groups

Sulfonic acid groups in sulfonoethylated cottons act as built-in catalysts for the reaction of cotton with substituted cyclic ureas. The cotton in the acid form did not require an additional catalyst for its reaction in aqueous media with dimethylolethylene urea, dimethylolpropylene urea, dihydroxyethylene urea, and dimethyloldihydroxyethylene urea. The strong acid groups of SE-cotton were more effective than carboxylic or phosphonic acid groups of carboxymethylated and phosphonomethylated cottons of like degree of substitution with each urea. Only the dimethyloldihydroxyethylene urea was effective in a delayed-cure process which, compared to the untreated control and the SE-control, imparted improved wrinkle recovery properties.