Search

For the first time, tannin-lignin-formaldehyde and tannin-lignin-furfuryl organic gels were obtained on the basis of larch bark tannins and hydrolysis lignin by sol-gel condensation with formaldehyde and furfuryl alcohol. Their physico-chemical properties were studied by varying the content of lignin (from 5 to 30 wt%) and a fixed mass ratio of polyphenolic substances to the crosslinking reagent (1 : 1.5). With an increase in the lignin content the density of tannin-lignin formaldehyde gels decreases from 0.83 to 0.53 g/ cm3, and that of tannin-lignin-furfuryl gels is from 0.32 to 0.14 g / cm3. According to the FTIR data, the structures of tannin-lignin-formaldehyde and tannin-lignin-furfuryl gels are formed by aromatic fragments cross-linked with methylene and methylene-ether bridges. Scanning electron microscopy shows that the addition of appropriate amounts of lignin to tannins (up to 10 wt% when using formaldehyde and up to 20 wt% when using furfuryl alcohol) promotes the formation of gels with a more developed porous structure. In the case of tannin-lignin-formaldehyde gel, the specific surface area and sorption of methylene blue are 12 m2 / g and 43 mg / g and for tannin-lignin-furfuryl gel – 72 m2 / g and 114.5 mg/g, respectively. It was found that an increase in the lignin content in the gel composition over 20 wt.% is accompanied by the phase localization of lignin (precipitation), which reduces the strength of the resulting gel and reduces its specific surface area.

The new method of producing of microfibrillated cellulose (MFC) from spruce wood was described. This method includes the stages of cellulose obtaining by peroxide delignification of wood in the medium “acetic acid-water-H2SO4 catalyst” and cellulose acid hydrolysis, ultrasonic treatment, and freeze drying. The structure of cellulosic products was studied by FTIR, XRD, SEM, AFM, dynamic light scattering methods. The particle size of final cellulosic products is characteristic of microfibrillated cellulose according to the TAPPI Standard WI 3021 classification. The particles of the MFC are characterized by a rather high surface charge, and its aqueous suspension showed a high colloidal stability for a long time. According to the AFM data the surface of the microfibrillated cellulose film is formed by homogeneous spherical particles with a diameter about 80 nm and does not contain external inclusions. The new method of obtaining MFC from spruce wood is less energy-consuming and more environmentally friendly compared to traditional technologies due to single-stage production of high quality cellulose without the use of sulfur- and chlorine containing delignifying agents, increased pressure and high water consumption.

The IR spectra and molecular mass distribution of arabinogalactan sulfates in the form of sodium and ammonium salts, obtained using various sulfating reagents, were compared. According to the obtained data, the sulfated derivatives of arabinogalactan differ from each other by the nature of the hydrogen bonds and the molecular weight distribution. Using coagulological tests at the activation of coagulation of platelet-poor human plasma, in vitro study of the anticoagulant properties of arabinogalactan sulfated derivatives in various salt forms differing in methods of preparation, degree of sulfation and molecular weight was conducted. It was established that the sample in the form of arabinogalactan sodium salt (SAG 1) with a sulfur content of 13.2 wt.% аnd a polydispersity degree of 1.52 showed 2 times more anticoagulant activity than the sample in the form of ammonium salt of arabinogalactan (SAG 2) with the sulfur content of 6.6 wt.% and the degree of polydispersity of 1.30. Antithrombin (aIIa) activity of samples obtained by sulfation with pyridine and sulfuric anhydride complex (SAG 1) and sulfamic acid complex (SAG 2) was, respectively, 23.42±1.86 and 10.20±1.50 U/mg; the anti-factor Xa activity of SAG 1 and SAG 2 was 2.13±0.42 and 0.37±0.08 U/mg; and the ratio aIIa/aXa for SAG1 and SAG 2 was 11 and 28, respectively. The less activity of antifactor Xa(aXA) of SAG as compared to unfractionated heparin (UFG) and higher rations of activities aIIa/aXa may contribute the less provocation of bleeding by SAG samples in the comparition with UFG.

The effect of a bifunctional catalyst containing nano-dispersed ruthenium particles on an oxidized carbon support “Sibunit” on the yield and composition of products in the processes of hydrogenation of abies wood and abies ethanol-lignin in a supercritical ethanol medium at 250° C was studied. The presence of Ru/C catalyst resulted in a raise the ethanol-lignin conversion from 85 to 98 wt.%, the yield of liquid product from 75 to 85 wt.%, the yield of gases – by 1.5 times, but the yield of solid products dropped from 14 to 2.8 wt.%. Ruthenium catalyst increased the conversion of abies wood by 12.5 wt.%, but did not affect the yield of liquid products. The yield of the solid residue in the presence of the catalyst was reduced by 12.5 wt.%, and the yield of gases rose by 2.5 times. Simultaneously, the ruthenium catalyst promoted the process of hydrodeoxygenation of liquid products, diminution their average molecular mass from 1174 g/mol to 827 g/mol and the formation of monomeric and dimeric compounds with a molecular mass 193 and 426 g/mol, respectively. The solid residue of catalytic hydrogenation contained 70.1 wt.% of cellulose. Thus, the application of Ru/C catalyst in the process of hydrogenation of abies wood allowed the reductive fractionation of wood biomass into a solid cellulose product, liquid and gaseous products from lignin and hemicelluloses.

Показана возможность получения биокомпозитных удобрений пролонгированного действия пропиткой пористой подложки из коры лиственницы водным раствором К2НРО4. Определены условия щелочной обработки коры лиственницы, позволяющие получать пористые подложки с низким содержанием водорастворимых веществ, токсичных для растений. В вегетационных тестах выявлено ростостимулирующее действие пористых подложек из коры лиственницы в зависимости от содержания в них водорастворимых веществ. Изучено влияние природы соли, температуры сушки пропитанной подложки и условий ее кислотной обработки на вымывание водой фосфатов и калия из биокомпозитных удобрений. Осуществлен подбор условий получения, обеспечивающих наибольшую устойчивость фосфор-калийного удобрения к вымыванию водой активных компонентов. Установлено, что удобрение на основе коры лиственницы способно к медленному выделению активных компонентов в течение длительного времени. Экспериментально установлено, что из удобрения, полученного в оптимальных условиях, в течение 10 сут. вымывается водой 43,6% фосфатов и 53,3% калия, что обеспечивает эффект его пролонгированного действия. Показано, что разработанное биокомпозитное фосфор-калийное удобрение по устойчивости к вымыванию фосфатов и калия превосходит промышленное гранулированное удобрение., The possibility of preparation of biocomposite fertilizer with a long- time action by impregnation of porous support from larch bark by water solution of К2НРО4 was shown. The conditions of alkali treatment of a larch bark which can provide porous supports with a low content of the soluble substances toxiferous for plants. The growth stimulate action of porous supports from a larch bark depending on the soluble substances contain into them was revealed at vegetation tests. Effect of salt natural, temperature of an impregnated support drying and conditions of her acid treatment on the phosphates and potassium leaching by water from biocomposite fertilizers was studied. Choice of the preparation conditions providing the greatest resistant of phosphorus-potassium fertilizer for active components leaching by water was held. It was determined, that the fertilizer based on larch bark is able to slow release of active components in long time. In experiments were find that 43,6 % phosphates and 53,3 % potassium are leaching by water due 10 days from the fertilizer obtained at optimum conditions, that provides their effect of a long-time action. It was shown, that the developed biocomposite phosphorus-potassium fertilizer surpass in resistant to phosphates and potassium leaching a commercial granulated fertilizer.