The review considers the current ideas of a relatively new field of "green chemistry" in the field of chemical processing of renewable natural plant raw materials. For a number of processes, the ways, methods and some technological aspects of obtaining new compounds and reagent systems, biodegradable compositions and "green chemistry" products that are in demand in various sectors of the economy, industry and life support of society are shown. The article presents the results of the analysis of Russian and world reserves of forest resources according to authoritative modern sources and proposals for their conservation and restora-tion. The problems of biorefiling of plant raw materials are described, one of which is the val-orization of lignin-the aromatic component of the chemical composition of wood. It is pro-posed to obtain biodegradable systems and compositions based on the by-product of wood processing lignosulfonate of a neutral production method characterized by a high content of polysaccharides in the hemicellulose of the carbohydrate part of wood after the separation of cellulose. The ways of using modified cellulose products as inhibitors of salt deposition and gas hydrate formation, and the areas of their application in oilfield chemistry are shown. Lig-nin and other components of plant resources have long been the basis of various classes of fi-bers of natural origin, including plant and animal origin, artificial fibers. In the sector of cre-ating materials with new properties that have a wide range of practical applications, the review describes the production of PLA polylactide synthesized from lactic acid as a modern alterna-tive to many synthetic polymers obtained from refined petroleum products. For the products of the interaction of ammonium lactate and N-butyl alcohol, a kinetic model for the production of butyl lactate, an intermediate product of green chemistry, is described. The results of the study of a specific class of compounds – ionic liquids – traditionally considered as so-called "green solvents" are presented. An approach to the creation of a mathematical model by calculating the adsorption characteristics for evaluating the effectiveness of systems and composites based on biodegradable polymers in the direction of "green chemistry" is proposed.

The article proposes a method of increasing the amount of OH-phenolic functional groups in the composition of a macromolecule lignosulphonate, a sulfo-derivative natural lignin polymer, tested under laboratory conditions by step-by-step chemical treatment of the lignosulphonate matrix with a solution of a bromine derivative, then with a solution of neutral sodium sulfite. This makes it possible to solve the problem characteristic of modern lignosulphonates of neutral sulfite production method, which have low values of tannidicity index: content of OH-phenolic groups, quantitative content of which forms inhibitory (tanning) capacity of lignosulphonates. The proposed procedure involves carrying out said demethylation reaction with cleavage of methyl group contained in phenylpropane unit of lignosulfonate. Pyrocatechin groups are formed and methanesulfonic acid molecule is cleaved off. The obtained product was analyzed by UV spectroscopy and the increase in optical density in the area of absorption of 280 nm characteristic of OH-phenolic functional groups was shown, which is the basis for the appearance of pyrocatechin structures in the phenylpropane unit of lignosulfonate. Proposed method allows increasing quantitative content of OH-phenolic groups in macromolecule composition from 1.7% of initial to 6.5%. The obtained results are correlated with the data on determination of tannidicity index - one of objective characteristics of inhibitory (tanning) capacity of lignosulfnates, which is 32%, compared to similar characteristic of undemethylated neutral lignosulfonate, where the value did not exceed 21%. The data show that demethylation of the lignosulphonate matrix is possible by converting modern inactive neutral lignosulphonates from the low-demand waste category of the pulp and paper industry to a promising raw material component.

В работе рассмотрены основные компоненты и продукты переработки древесины, отходов сельхозугодий, отходов целлюлозно–бумажной промышленности и квалифициро-ваны как источники пентозансодержащего ресурсовозобновляемого отечественного сырья. В статье подробно отмечены структурные компоненты древесины, как природного поли-мера, в составе которого присутствуют ароматическая и углеводная части. Отмечено, что указанные полимеры перспективны как исходные сырьевые компоненты для получения по-лезных продуктов химии. Рассмотрена роль лигнина, целлолозы и гемицеллюлоз в оформле-нии механических и структурных свойств древесины. Показаны особенности химических превращений мономерного ароматического звена лигносульфоната – фенилпропановой еди-ницы в процессах делигнификации древесины, основные химические реакции делигнификации древесного сырья в условиях сульфитной и нейтрально-сульфитной варок. Предложена ме-тодика количественного определения моносахаридов в составе углеводной части сульфиро-ванных производных лигнина – лигносульфонатов методом тонкослойной хроматографии. Показаны схемы основных химических реакций синтеза продуктов на основе фурана, тетра-гидрофурана и хлорпроизводных фурана и некоторых соединений на их основе из пентозан-содержащего сырья. Представлены результаты сравнительных исследований антибактери-альной активности реагентов на основе фуранпроизводных пентоз, полученных из углевод-ной части нейтрально-сульфитных лигносульфонатов. В статье рассмотрены особенности реакций сульфирования мономерного звена лигнина в зависимости от рН среды: кислой, нейтральной и щелочной. Выделены такие три основные реакции, одновременно происходя-щие с лигнином в процессе делигнификации древесины при сульфитной варке, как реакция сульфирования, реакция гидролитической деструкции, реакция конденсации. Показано, что в составе лигнин-гемицеллюлозной матрицы присутствуют три вида взаимосвязанных сет-чатых структур: самого лигнина; сетки ковалентных связей лигнина с гемицеллюлозами и сетки, структура которой получена за счет водородной связи между и сил физического вза-имодействия лигнина и гемицеллюлоз. В статье показана перспективная возможность рас-ширения области применения инактивных и маловостребованных нейтрально-сульфитных лигносульфонатов, возможность их фракционирования с получением новых соединений, об-ладающих повышенными бактерицидными и дубящими свойствами. Изучена их сравнитель-ная способность по отношению к известному реагенту-бактерициду гексаметилентера-мину и установлена сопоставимость их воздействия на устойчивость буровых систем к бак-териальной агрессии.

Objectives. Cinnamic acid derivatives belong to a large class of phenolic compounds, which are widely distributed in plants and have high potential for use in the medical and industrial fields. They have various useful practical properties, e.g., antioxidant, anti-inflammatory, antiplatelet, and anti-melanogenic properties. Hydroxycinnamic acids are of particular interest as phenylpropanoids, which are the starting compounds of lignin. The aim of this work was to study the electronic structure and analyze the reactivity of the simplest representatives of phenylpropanoids formed during the biosynthesis of the coumaric (p-hydroxycinnamic), caffeic (3,4-dihydroxycinnamic), ferulic (3-methoxy-4-hydroxycinnamic), sinapic (3,5-dimethoxy-4- hydroxycinnamic), and 3,4-dimethoxycinnamic acids. These acids are the biogenetic precursors of most other phenolic compounds (coumarins, melanins, lignins, and flavonoids) and are found in almost all higher plants.Methods.Calculations with full optimization of the geometric parameters were performed using the original Hartree–Fock theory and hybrid density functional method. All calculations were performed using the Firefly program.Results.A comparative quantum chemical calculation of the geometric parameters of hydroxycinnamic acid molecules was conducted via two methods, and the values of the charges on atoms according to Mulliken were determined. It was found that with the addition of hydroxyl and methoxy substituents at the meta and para positions relative to the carboxyl fragment, the electron density shifts toward the benzene ring, and the symmetry of the molecule decreases. Additionally, in these structures, there is π,π-conjugation of the carboxyl fragment of the –СН=СНСООН molecule with the aromatic ring, which significantly affects the geometric configuration of the molecule. The maximum positive charge is concentrated on the C9 atom, while the maximum negative charge is on the oxygen atoms belonging to the methoxy substituents and the hydroxyl group, which confirms the role of oxygen atoms in the chemical transformations of acids.Conclusions.Two different methods were used to calculate the geometric, electronic, and energy parameters and electrophilicity indices of the studied hydroxycinnamic acids in the gas phase. The obtained values were consistent (within the limits of error) with the experimental data as well as the results described in earlier works’ calculations by other methods.

Polyacrylamide and polyacrylamide/polysaccharide hydrogels exhibiting high structural and mechanical properties, along with acceptable gelation times and gelant viscosity, are proposed for water shutoff applications in high-temperature reservoirs. The obtained polyacrylamide gels demonstrate an elastic modulus 1.6–2.7 times higher than that of the baseline polyacrylamide–resorcinol–paraform–sulfamic acid gel (17.2 Pa), reaching up to 46.3 Pa, while the polyacrylamide/polysaccharide gels surpass it by a factor of 2.3–5.2, reaching up to 89.9 Pa. The gelation time of the polyacrylamide/polysaccharide gels ranges from 3 to 7 h, with the gelant viscosity varying from 685 to 2098 mPa·s at a shear rate of 100 s⁻¹. Crosslinking of polyacrylamide with polysaccharides was achieved using paraform. Using the gel based on crosslinked polyacrylamide with xanthan as an example, spectral methods characterized the copolymer constituting the basis of the plugging material. Our analysis established that crosslinking occurs between the amide group of polyacrylamide and the hydroxyl group of the polysaccharide. Model reactions with low-molecular-weight analogs (glucose, acetamide, and formaldehyde), coupled with mass spectrometric confirmation of the structure of the resulting products, revealed possible reaction pathways. The crosslinking of polyacrylamide was investigated using a broad range of polysaccharides of plant and microbiological origin. The resulting series of hydrogels, possessing the suite of properties required for water shutoff in high-temperature formations, will enable oil companies (operators) and service firms to select a specific gel-forming system based on project objectives, logistics, and budget constraints.