Abstract: Chlorophyll was extracted from willow leaves by ultrasound-assisted extraction method in which 95% EtOH was used as solvent. Sodium copper chlorophyll was prepared by the processes of saponification and copper substitution. Maximum absorption and the ratio of absorbance were obtained by ultraviolet-visible spectrum analysis. The ratio of absorbance is 3.83 which indicates that the quality of sodium copper chlorophyll prepared can come up to the standard of GB 3262-1982. Sodium copper chlorophyll was used to dye flax fabric. In the tests, dyeing rate and color characteristic value(whiteness, L^*, a^*and b^* values) were used as analysis indexes and the effects of concentration of each factor on dyeing results were discussed to obtain optimum process conditions as follows: mass concentration of dye solution 1 g/L, concentration of accelerating agent 60 g/L, bath ratio 1:20(g:mL), dyeing under the temperature of 98℃ for 50 min. Finally, the colorfastness of the flax fabric dyed under the best conditions, such as wash fastness, rubbing fastness and light fastness were tested. The results show that rubbing fastness is superior and wash fastness is good, however, light fastness is inferior. Dye, blank and dyed flax fabric were analyzed by FT-IR method to investigate the interaction between sodium copper chlorophyll and flax fiber. Surface appearances of blank and dyed samples were observed by SEM. The results indicate that there exist a few hydrogen bonds between sodium copper chlorophyll and flax fiber and that sodium copper chlorophyll disperses among fibers uniformly.

Key words: sodium copper chlorophyll, dyeing conditions, colorfastness