Topochemical Mechanisms Involved in the Preparation and Deacetylation of Partially Acetylated Cottons

Abstract

Iodine sorption and moisture sorption data and some density, x-ray, and infrared data have been obtained on partially acetylated (PA) cottons before and after progres sice deacetylation with 2 N hydrochloric acid or with N 2 sodium hydroxide. The re sults substantiate the accepted theory that in the partial acetylation of cotton the amor phous regions are acetylated first. They also show that deacetylation of PA cottons by these two reagents proceeds by different mechanisms. With hydrochloric acid. the acetylated amorphous cellulose is deacetylated more or less completely throughout the fiber before the, acetylated crystalline is attacked. With sodium hydroxide both are de acetylated simultaneously with little or no selectivity, so that deacetylation proceeds annu larlv from the surface of the fiber inward.