The effects of alkali pretreatment on the properties of acetylated cotton fabrics were studied.
It was found that although the reaction of acetylation was very much accelerated by alkali pretreatment before acetic acid treatment in the liquid phase method, the strength of the acetylated fabrics did not be lower at all.
The cotton fabrics acetylated after alkali treatment have higher strength than ordinarily acetylated ones without alkali treatment and the fabric elongations become larger with the increase of acetylation. The moisture regain is relatively higher than ordinarily acetylated ones, although it becomes lower with the acetylation up to 50 mole %. The specific gravity becomes lower linearlly with acetylation, but is in general lower than ordinarily acetylated ones. The acid-resistances become better proportionally with the acetylation up to 50 mole %, although the ordinarily acetylated fabrics have almost the same acid-resistance in a wide range of acetylation beyond 30 mole %.
This difference between the alkali pretreated acetylation and the ordinary acetylation would be due to the difference in the reaction mechanism. The effects of alkali pretreatment would be caused by the decrystallization effects on the cotton cellulose.