Multifunctionality of nitrogen oxide compounds as a basis for preparation of practically important cellulose materials

Abstract

The experience of using the multifunctional character of nitrogen oxide compounds (N204, N02, N203, HN03) in cellulose chemistry and technology is summarized. The approach discussed is based on the ability of the nitrogen oxide compounds to act as multi-purpose reagents with respect to cellulose, enabling oxidation, nitrosation, nitration, hydrolytic cleavage or adduct formation to be performed on cellulose, depending on reaction conditions. It is often possible to perform simultaneously several chemical or/and structural cellulose modifications using a sole reagent in a «one-pot» process. High solubility of nitrates formed from mineral components of vegetal tissues, along with high reactivity of HN03 toward lignin that occurs together with cellulose, provide the possibility of selective extraction of radionuclides in the course of nitric acid delignification of contaminated vegetal material. In this review, examples are given of effective use of multiple functionality of nitrogen oxide compounds in the preparation of such practically important materials as totally or partially substituted cellulose acetates soluble in organic solvents, water-soluble polysaccharide sulphates with low degree of substitution, powder forms of cellulose hydrate and of carboxylated cellulose in both structurally disordered and microcrystalline forms, as well as in isolation of radionuclide-free cellulose and nitrolignin from contaminated agricultural residues.