Abstract
Fibrous acetylation of cotton fibers with acetic anhydride vapor was carried out using ZnSO4 and ZnCl2 as catalyst. In the case of ZnSO4-catalyst the acetylation proceeded smoothly and highly acetylated fibers without serious damage were obtained, while in the case of ZnCl2-catalyst it was difficult to attain any high degree of acetylation without using more concentrated catalyst solution.
Reacetylation rate, chloroform and aceton solubility and water absorbency of fibers which had been acetylated with various catalysts were compared. It seem that in the case of ZnCl2-catalyst the amorphous part reacts selectively so that the reaction of the crystalline part follows very slowly. Apparently the type of reaction with sulfuric acid and ZnSO4 is similar.
