Abstract: A catalytic system for cellulose acylation includes an adduct of sulfuric acid with N,N-dimethylacetamide, free sulfuric acid or free N,N-dimethylacetamide with the following mole ratio of the components: adduct:1.0; free sulfuric acid, max:0.49; or free N,N-dimethylacetamide, max:0.4. A process for producing such a catalytic system is based upon reacting sulfuric acid with N,N-dimethylacetamide in an anhydrous medium at a temperature of 0° C.-25° C. with the following mole weight ratio of the components: sulfuric acid:1.0; N,N-dimethylacetamide, max:1.4. A process for cellulose acylation in the presence of this catalytic system incorporates cellulose treatment with acetic acid followed by treatment of the resultant activated cellulose with a lower fatty acid anhydride at a temperature of 10° C.-90° C. in the presence of this catalytic system taken in an amount of 1.5-30.0 wt.

Abstract: A catalytic system for cellulose acylation includes an adduct of sulfuric acid with N,N-dimethylacetamide, a lower fatty acid having from two to four carbon atoms, and free sulfuric acid or free N,N-dimethyl-acetamide. A mole ratio of the system components per mole of the adduct is presented. The catalytic system also includes an adduct of perchloric acid with N,N-dimethylacetamide for use in cellulose reactions with propionic or butyric anhydride. Method for preparing the catalytic system includes the use of hydrous sulfuric acid or sulfuric and perchloric acids, and N,N-dimethylacetamide and include reacting hydrous sulfuric acid or sulfuric and perchloric acids with N,N-dimethylacetamide in the presence of a lower fatty acid anhydride in an amount of 1 mole per mole of water contained in the reactants in the absence of cellulose at a temperature of from 0.degree. C. to 25.degree. C. Mole ratios of the reactants for preparing the catalytic system per mole of sulfuric acid are presented.