Effect of Concentrated Alkali Treatment on the Properties of Naturally Colored Brown Cotton

摘要

The naturally colored cotton fiber was treated by sodium hydroxide solution with different concentrations and temperatures. The surface morphology, crystalline structure, mechanical properties and color feature value of fiber after treatment were tested by SEM, XRD, electronic single fiber strength tester and Computer Color Matching meter. The results show that the longitudinal convolutions of the naturally colored cotton fiber treated by concentrated sodium hydroxide decreased or disappeared, and the fiber became nearly cylindrical or cylindrical. The crystallinity of fiber after treatment decreased, part of the cellulose I changed into cellulose II. The breaking strength and breaking elongation of fiber after treatment increased. The total color differences (ΔE) and value a* of fiber after treatment increased, to the contrary, value L* and value b* decreased, which leaded to that the color of fiber treated by alkali became darker. In addition, the treatment temperature had larger influence on the properties of fiber.