| abstract |
1521125 Cellulose nitrites, sulphates and nitrates R G SCHWEIGER 8 July 1975 [10 July 1974] 28676/75 Heading C3A Nitrite esters of cellulose which may be converted to sulphates or nitrates are prepared by reacting water-containing, cellulose having not more than 12% water content with dinitrogen tetroxide or nitrosyl chloride at less than 50‹ C. with stirring in the presence of at least three parts by weight of a swelling or solubilizing solvent for the nitrite ester per part by weight of cellulose in the presence of proton acceptor. The cellulose preferably contains 4-12% water by treatment with a highly polar aprotic solvent. The solvent used is N,N-dimethylformamide and the highly polar aprotic solvent may be N,N-dimethylformamide, N,N-dimethylacetamide or pyridine. The sulphate ester may be prepared by reacting the nitrile ester with SO3 or a complex thereof and neutralizing with a base to give the alkali salt form. |