Crosslinking of partially carboxymethylated cotton fabric via cationization

Abstract

A novel method for non-formaldehyde easy care finishing of cotton fabric based on ionic crosslinking has been examined. Accordingly, the cotton fabric was first partially carboxymethylated to impart to it the anionic character through its reaction with monochloroacetic acid in alkaline medium. Application of reactive cationic agent in alkaline medium affects crosslinking of the resulting anionic cotton in a second step. The reactive cationic agent used was 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (Quat-188). Factors affecting the quaternization reaction of partially carboxymethylated cotton fabric (PCMC) have been studied. These factors include NaOH concentration, reaction time and temperature, quaternizing agent concentration as well as material to liquor ratio and method used for quaternization. The latter includes two methods, namely, the exhaustion method and the cold pad-batch method. Correlations between the degree of crosslinking (expressed as nitrogen and carboxyl content) of quaternized PCMC fabric and the easy care properties were also made. Easy care properties include wet and dry crease recovery angles as well as tensile strength and elongation at break. Results obtained signify that: (a) optimum conditions for cationization of PCMC fabric are obtained when the Quat-188/sodium hydroxide molar ratio is 1/2 using the cold pad-batch method for 24 h; (b) the extent of cationization reaction, expressed as percent nitrogen, increases as the carboxyl content of the PCMC fabric increases, and (c) both wet and dry crease recovery angles of PCMC samples exhibit much higher values compared with that of untreated samples while both tensile strength and elongation at break display marginal improvements. These improvements depend mainly on the degree of ionic crosslinking.