Abstract:

In order to avoid the harmful influence on human health by nonecological dyes and additives, the swelling and dissolution behavior of naturally colored cotton in [BMIM]Cl (1-butyl-3-methylimidazolium chloride) were investigated by optical methods. The effects of reaction temperature, reaction time, and pretreatment were studied. The results showed that brown cotton, green cotton and white cotton all balloon swollen followed by completely dissolving in [BMIM]Cl ionic liquids, but their solubility was different. The pigment substance of green cotton spread out from the fiber lumen during the balloon swelling and dissolution while the pigment of brown cotton did not. Both the alkaline and enzymatic pretreatment can increase the swelling ratio of the fiber. But the ballooning phenomenon of cotton fiber disappeared after the enzymatic pretreatment. The time required to reach maximum swelling decreased and the fiber diameter at maximum swelling increased with the increasing of ionic liquid temperature.