An Investigation Into The Chemical Modification And Dyeing Of Cotton Fabric

In this paper, PECH-amines were used to modify cotton fabric in order to improve its dyeability. the methods and conditions of modification and dyeing were studied in detail. The aim is to solve the lower percent of dye utilization and the serious environment pollution problem caused by high salt dosages and residual dyes in dyeing solution. Through the suitable modification before dyeing, cotton fabric can be dyed in the condition of free salts and alkalis. Thus, cleaning dyeing production and environment protection can be realized, and the water and dyes can also be saved.Chemical modification experiments have been primarily studied. The modified methods and modification parameters were optimized. The results have showed that the optimum conditions of exhaustion process are: PECH-amine 6～8g/L, NaOH 6～8g/L, liquor ratio 20:1, 80℃, 30 min; and the optimum conditions of pad-dry-bake procedure are: PECH-amine 8-10 g/L,NaOH 8～10g/L, 130℃, 1min.The tests of stripping dyes from dyed cotton have indicated that the binding force between modified cotton fiber and acid dyes is electrovalent bond, and that the binding force between modified cotton fiber and direct dyes are hydrogen bond and Van Der Waals force and electrostatic attraction force, and that reactive dyes not only can covalently bind with modified cotton fiber by nucleophilic reaction, but also can interact with cotton fiber through electrovalent bond which can accelerate the uptake and reaction of dyes.The dye performance of modified cotton fabric was investigated. The results have revealed that the dyeing rate of cotton fiber is accelerated due to chemical modification, and that the dry and wet rubbing fastness and washing fastness of cotton fabric modified with PECH-amines are the same as that of the unmodified cotton fabric. The levelness and penetrability of cotton fabric modified by PECH-amine is good in the case of fully stirring.The wearing performance of cotton fabric modified with PECH-amines was measured. The results have showed that the breaking strength, elongation at breaking, elastic recovery, handle, drapability, abrasion resistance and hygroscopicity are very good.