Abstract
Fibrous Acetylation of cotton and ramie yarn with acetic anhydride vapor was carried out using sulfuric acid and ZnSO4 as catalyst. The count of yarn has scarecely any influence on the rate of the acetylation. Raw cotton yarn reacts somewhat slower than the bleached yarn. Evenness of dyeing of acetylated yarn is comparatively good. When ZnSO4 was used no loss of tensile strength was observed. The shrinkage of cotton yarn by acetylation increases with increasing degree of the acetylation and finally ammounts to 20%, but this shrinkage may be avoided when some tension is applied by the acetylation.
Ramie yarn can be acetylated as smoothly as cotton yarn but the shrinkage is much less than in the latter.
