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Spruce (Piceaabies) wood hemicelluloses have been obtained by the noncatalytic and catalytic oxidative delignification in the acetic acid-water-hydrogen peroxide medium in a processing time of 3–4 h and temperatures of 90–100 °C. In the catalytic process, the H2SO4, MnSO4, TiO2, and (NH4)6Mo7O24 catalysts have been used. A polysaccharide yield of up to 11.7 wt% has been found. The hemicellulose composition and structure have been studied by a complex of physicochemical methods, including gas and gel permeation chromatography, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The galactose:mannose:glucose:arabinose:xylose monomeric units in a ratio of 5:3:2:1:1 have been identified in the hemicelluloses by gas chromatography. Using gel permeation chromatography, the weight average molar mass Mw of hemicelluloses has been found to attain 47,654 g/mol in noncatalytic delignification and up to 42,793 g/mol in catalytic delignification. Based on the same technique, a method for determining the α and k parameters of the Mark–Kuhn–Houwink equation for hemicelluloses has been developed; it has been established that these parameters change between 0.33–1.01 and 1.57–472.17, respectively, depending on the catalyst concentration and process temperature and time. Moreover, the FTIR spectra of the hemicellulose samples contain all the bands characteristic of heteropolysaccharides, specifically, 1069 cm−1 (C–O–C and C–O–H), 1738 cm−1 (ester C=O), 1375 cm−1 (–C–CH3), 1243 cm−1 (–C–O–), etc. It has been determined by the thermogravimetric analysis that the hemicelluloses isolated from spruce wood are resistant to heating to temperatures of up to ~100 °C and, upon further heating, start destructing at an increasing rate. The antioxidant activity of the hemicelluloses has been examined using the compounds simulating the 2,2-diphenyl-2-picrylhydrazyl free radicals.

The "green" synthesis of galactomannan sulfates using a sulfamic acid-urea mixture has been studied for the first time. The effect of the time and temperature of the galactomannan sulfation process on the degree of substitution of galactomannan sulfates has been investigated. It is shown that, at a temperature of 70°C with an increase in the process time up to 120 min, the degree of substitution increases up to 0.70. An increase in the process temperature up to 80°C leads to the production of galactomannan sulfates with a degree of substitution of 1.67. With a further increase in the process temperature to 90°C, the galactomannan structure is partially destructed, and the degree of substitution decreases. Embedding of the sulfate groups into the galactomannan structure has been confirmed by elemental analysis and Fourier-transform infrared spectroscopy. In addition, the initial and sulfated galactomannans have been characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and gel permeation chromatography. The thermal analysis shows that the initial galactomannan exhibits endothermic peaks at 254 and 294°C and an exothermic peak at 315°C, while sulfated galactomannan exhibits endothermic peaks at 209 and 275°C and an exothermic peak at 281°C. Using atomic force microscopy, it has been shown that the sulfated galactomannan film consists of spherical particles with an average diameter of 200-300 nm; according to the phase contrast data, it has the uniform composition without extraneous impurities.

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Colloids formed by the direct interaction of aqueous Cu2+ ions and xanthates were characterized along with their precipitates incorporating dixanthogen.

The composition and physicochemical characteristics of polysaccharides extracted from spent liquors of catalytic and noncatalytic delignification of larch wood in the acetic acid-hydrogen peroxide medium were studied. The following were used as catalysts: (NH 4 ) 6 Mo 7 O 24 , MnSO 4 , TiO 2 , and ZnSO 4 . The structure of polysaccharides was identified by FTIR and NMR spectroscopy. Their composition was established using gas chromatography, and the physicochemical characteristics were studied using gel permeation chromatography, scanning electron microscopy, thermogravimetric analysis, gas adsorption, and elemental analysis. It was shown that in the process of oxidative delignification, a significant amount of hemicelluloses and arabinogalactan passes into the spent liquor. The yield of polysaccharides was up to 16.9 wt%. Polysaccharides had a weight-average molecular weight of up to 22.9 kDa and a narrow molecular weight distribution.