Application of cationic modification agent to dyeing of cotton with natural dyes

In view of the low dye-uptake and poor color fastness of natural dyes on cotton fabrics,a quaternary ammonium salt based cationic modification agent was synthesized and applied to the cotton.The modification mechanics was studied and the changes of cotton fiber structure before and after modification were analyzed by FTIR and XRD.The modification processes were optimized by single factor tests.The results indicated that the modification agent improves the dyeing performance of natural dyes on cotton fabrics.With 15 ~ 21 g/L of modification agent,4.5~5 g/L of sodium hydroxide at 60~70℃for 50~60 minutes,theK/Svalue of the modified cotton increased obviously.The washing fastness of the modified cotton was rated Grade 4 and the crocking fastness,Grade 3.