Much focus is being dedicated to the development of innovative technologies for producing biodegradable polymers from plant biomass. It is proposed that annual and perennial herbaceous plants, such as miscanthus, be used as promising sources of cellulose. The component composition of miscanthus allows us to consider it as a raw material for obtaining cellulose. This paper proposes methods for cooking miscanthus lignocellulose raw materials, which allow sulfate cellulose to be obtained with a high yield (up to 52%). In the process of obtaining chemical–thermomechanical pulp, the product yield is 71%. The possibility of replacing unbleached sulfate pulp with a semi-finished product from miscanthus for paper production is considered. For all types of raw materials obtained, acceptable paper-forming properties are observed. The best strength and deformation properties are obtained for sulfate cellulose. The addition of this cellulose to the composition of waste paper fluting significantly increases the sheet density, elasticity, and energy capacity without losing tensile strength. Using miscanthus raw materials along with waste paper of grade MS 5B makes it possible to make a composite product. The resulting products have optimal mechanical properties for creating the middle layer of corrugated cardboard. Miscanthus cellulose can be considered a promising raw material for enhancing waste paper fluting. Altering the system composition utilizing miscanthus and waste paper enables a broad modification of the mechanical and optical qualities of the resultant paper. The recommended concentration of miscanthus fraction in waste paper fluting is 30%.

This study analyzes the effect of artificial aging on the mechanical deformational and optical properties of various paper samples, which allows us to evaluate their durability and suitability for long-term storage. The methods of accelerated aging, measuring the breaking length, specific resistance, elongation, and fracture strength, were used, and the optical characteristics were estimated by the R₄₅₇ and CIE whiteness indices, as well as opacity. Mechanical measurements (breaking length, specific resistance, elongation, and fracture strength) revealed that bleaching reduces residual lignin and strengthens interfiber bonds, boosting pine pulp strength by up to 8%. Optical properties initially improve slightly, then increase sharply after the second bleaching cycle and stabilize, while opacity decreases, providing greater light transmittance. After accelerated aging, the following deterioration is observed: for bleached samples, R₄₅₇ whiteness changes; and for unbleached samples, CIE whiteness and opacity increase. After aging, aspen pulps and kraft papers retained over 90% of their initial strength and whiteness, whereas untreated and office papers lost up to 20–25%. These findings identify that aspen-based and kraft papers demonstrate better mechanical deformational and optical properties, which makes it possible to predict the operational characteristics of paper depending on the processing and aging methods used.

ABS plastic is an inexpensive material with attractive physical and chemical properties. Unfortunately, it is susceptible to degradation under UV radiation, so it limits the use of this material outdoors. In this paper, we demonstrate a low-cost approach to reduce the photodegradation of ABS plastic by using additives of kraft lignin and dioxane lignin as UV absorbers. Lignin is an abundant plant polymer, which is a waste product of the pulp and paper industry. Non-regular structure of lignin hampers its use in industry. However, there is possible use of lignin as an addition to enhance the properties of resulting materials. In this study, we obtained composites of ABS and lignin with the hot extrusion method. Adding up to 15% of lignin to ABS plastic does not have a significant negative impact on tensile properties. We irradiated the resulting composites with UV and studied the UV effects on their mechanical properties and chemical structure. Oxidative degradation was characterized by FTIR and 2D NMR methods. The results showed that small lignin additions reduced the photodegradation of ABS. The previously undescribed product of the degradation of the obtained composites was detected with the use of the set of 2D NMR spectra of the composites. We proposed a scheme for the formation of this photodegradation product based on the obtained data.

This paper studies a two-stage oxygen-alkaline treatment and subsequent bleaching of softwood sulfate pulp obtained from healthy and deadwood of spruce and larch. Delignification was carried out at elevated temperature and pressure in an alkaline medium with the addition of hydrogen peroxide, after which the pulp was subjected to classic ECF cycles with chlorine dioxide, hydrogen peroxide and, if necessary, elemental chlorine. The selected and washed mass was ground to a specified degree of grinding and formed into laboratory sheets of standard density on a sheet-forming apparatus. The results showed that oxygen-alkaline pretreatment significantly reduces the residual lignin content, and subsequent bleaching cycles make it possible to obtain high-brightness pulp with minimal losses of cellulose and viscosity. The structural, morphological and mechanical characteristics of the obtained samples were studied. After a full bleaching cycle, the fibers become slightly shorter and thinner, their surface is leveled, the proportion of small fractions decreases, and the homogeneity of the structure improves. The resulting cellulose samples demonstrate mechanical characteristics that meet industrial requirements for high-quality printing and thin-layer paper grades.

Данная работа посвящена рассмотрению возможности и обоснованию использования продуктов на основе технического хитозана как полисахарида животного происхождения в качестве добавки при изготовлении лабораторных образцов упаковочной крафт-бумаги с повышенной гидрофобностью. Цель работы – оптимизация условий получения упаковочной крафт-бумаги с использованием метода математического планирования эксперимента в соответствии с трехфакторным униформ-ротатабельным планом второго порядка Бокса-Хантера. Показана возможность эффективной гидрофобизации достаточно тонкого целлюлозного волокнистого материала, имеющего массу 1 м² 70 г. В исследованном факторном пространстве установлены математические зависимости, адекватно описывающие влияние основных технологических параметров – расхода хитозана (0.5–1.5%), степени помола бумажной массы (25–35 °ШР) и содержания в композиции хвойной целлюлозы (80–100%) на гидрофобность (повышение влагостойкости) бумаги и ее физико-механические характеристики. Показано, что в присутствии в композиции хитозана гидрофобность крафт-бумаги по показателю поверхностная впитываемость воды при одностороннем смачивании (метод Кобба) многократно усиливается и при максимальном расходе продукта (1.5%) достигает 24–25 г/м². При этом значения степени помола массы и содержание хвойной целлюлозы в композиции могут варьироваться в достаточно широком технологическом диапазоне в соответствии с исследованным факторным пространствам. Увеличение расхода хитозана, степени помола волокон и содержания хвойной целлюлозы в композиции одновременно обеспечивает прирост значений практически всех физико-механических характеристик лабораторных образцов упаковочной крафт-бумаги.