Cellulose-containing Materials Research Articles

The influence of reed nanocellulose on the quality indicators of paper-basis for wallpapers

Improving the production technology of products with improved quality indicators and with less impact on the environment remains an urgent scientific and practical problem of paper industry enterprises. This refers to the technology for the production of paper-bases for wallpaper using environmentally safe chemical additives, in particular nanocellulose (NC), which was obtained by acid hydrolysis from reed cellulose. The production of cellulose was carried out in two stages - extraction from reed stalks with a solution of alkali and an organosolvent method of cooking in a solution of peracetic acid. The obtained organosolvent cellulose contained the remains of lignin and mineral substances, which allows it to be used for the preparation of NC. As a result of the hydrolysis of organosolvent cellulose, a time-stable NC suspension was extracted, the properties of which were investigated by scanning electron microscopy (morphological changes in the structure of reed cellulose-containing materials), atomic force microscopy (determination of topographic characteristics of NC), analysis of electronic absorption spectra (transparency of NC films). It was established that reed NC films had nanoparticles with a cross-sectional size of 5-25 nm, density up to 1.52 g/cm3, transparency up to 81.6 %, tensile strength up to 65 MPa. For the production of castings of paper-bases for wallpaper samples, sulfated pine bleached cellulose and polyester synthetic fiber were used, to the fibrous mass of which were added the following chemical additives: alkyl ketene dimer, reed NC, binder, and optical brightener. It has been shown that the use of nanocellulose at a rate of 0.35 % to 1.0 % of the paper mass leads to a significant improvement in the physical and mechanical quality indicators of the paper base for wallpaper. It was established that the replacement of 50 % of the synthetic chemical auxiliary substance alkyl ketene dimer with nanocellulose or additional application of nanocellulose at a rate of 0.5 g/m2 on the surface of the casting with 0.7 % alkyl ketene dimer allows to obtain paper that meets the requirements of the standard. The obtained results indicate the prospects of using reed nanocellulose for the production of other mass types of paper and cardboard.

IN SITU SYNTHESIS AND STUDY OF TWO-PHASE HYBRID HYDROGELS OF β-CYCLODEXTRIN/CELLULOSE BY SCANNING ELECTRON MICROSCOPY AND FTIR SPECTROSCOPY

Two-phase hybrid hydrogels from powder cellulose (PC) and/or microcrystalline cellulose (MCC) and biologically active natural cyclic oligosaccharide β-cyclodextrin (β-CD) were obtained by combining them in the solvent N,N-dimethylacetamide/LiCl and regenerating the hydrogels from the solutions. Cellulose-cyclodextrin hybrid hydrogels were synthesized for the first time without use of cross-agents and/or other gel-promoting components, and without precipitants and anti-solvents under atmospheric conditions. The properties of the composites depended on the type of pristine cellulose and the method of combining the components. Optimally, composite hydrogels were obtained by combining a 1–3 wt.% solution of PC in DMAA/LiCl followed by the addition of β-CD powder to the solution. The water-retention capacity of MCC/β-CD hydrogel was 48.8 g g-1, that of deciduous and flax PC/β-CD hydrogels 62.9 and 55.5 g g-1 respectively. The morphology of the hybrid gels was characterized by scanning electron microscopy (SEM) and the functional content was determined by Fourier transform IR spectroscopy. It was shown that the hydrogels seem to be two-phase interpenetrating systems that interact at the interface. Both phases coexist as a monolithic agglomerate stabilized additionally by hydrogen bonds. Each phase has an individual shape and morphological structure. The results allow the use of cellulose-containing materials, including waste materials, in the elaboration of new hybrid materials to be predicted.

Биодеградируемые полимерные материалы на основе поливинилового спирта, крахмала и производных целлюлозы

The preparation of biodegradable composite materials based on polyvinyl alcohol, starch and cellulose is described. The resulting bioplastics are a promising basis for use as reinforcing polymer systems of cellulose-containing materials used for the production of packaging materials for various purposes. It has been shown that the use of starch and cellulose inclusions makes it possible to control the physical-mechanical properties of composites and obtain rapidly degradable nature-like materials for practical use under environmental protection conditions.

Study of the Possibility of Using Biodegradable Cellulose-Containing Materials Based on Miscanthus as Disposable Tableware and Food Packaging

Study of the Possibility of Using Biodegradable Cellulose-Containing Materials Based on Miscanthus as Disposable Tableware and Food Packaging

Production of activated carbon from exhausted coffee grounds chemically modified with natural eucalyptus ash lye and its use in the fluoride adsorption process.

The objective of this research was to produce an activated carbon (AC) from exhausted coffee grounds (ECG) and chemically activate it with natural lye from eucalyptus ash to subsequently evaluate the fluoride adsorption process in an aqueous medium. The thermal analysis of ECG was determined as well as solubilized extraction, alkalinity and calcium content of eucalyptus ashes. AC was characterized by elemental analysis, scanning electron microscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), analysis of textural properties, pH and point of zero charge (PZC). The AC presented macroporosity and XRD confirmed the amorphous characteristic of cellulose-containing materials. Carboxylic acid functional group was identified in the AC surface, which can contribute to the adsorption of fluoride. The specific surface area of ECG and AC were 189.01 and 21.74 m2/g. The adsorption kinetics of fluoride revealed that equilibrium is reached around 800min and the data followed the pseudo-second order model. The Freundlich model fitted the experimental data with the best quality and Freundlich's constant n allowed inferring that the adsorption is favorable and the isotherm appears to be L-type, with an initial downward curvature, which suggests less availability of active sites when increasing the adsorbent concentration.

Investigation by 3D Simulation of the Interaction of Fibers of a Multilayered Cellulose-Containing Material

Investigation by 3D Simulation of the Interaction of Fibers of a Multilayered Cellulose-Containing Material

Modification of Cellulosic Materials with Boron-Nitrogen Compounds

Wood fiber and its products are modified to increase fire and bio-resistance. The best results are achieved by using modifiers that enter into chemical interaction with the hydroxylated substrate, forming the organic matrix of the materials. The purpose of the research described in the article was to study the possibility of using boron-nitrogen compounds to modify cellulose and cellulose-containing materials to improve the performance, bio- and fire-protective properties of construction materials, as well as to optimize the consumption of boron-nitrogen compounds. As a result of the research, it was found that the boron-nitrogen compounds used in the compositions developed here chemically interact with hydroxyl groups at the C6-atom of cellulose. The chemical interaction of boron-nitrogen compounds with cellulose is an inter-crystalline process occurring without destruction of the crystal structure of the substrate since the modifier molecules bind with the more accessible hydroxyl groups of the amorphous regions of cellulose. Thus, surface modification with boron-nitrogen compounds does not result in accelerated aging of cellulose-containing materials and loss of strength but, on the contrary, increases the durability of wooden structures.

Fire protection of wooden building structures

The paper covers the issues of fire protection of cellulose-containing materials, in particular wood. It is shown that despite a number of valuable properties that wood possesses, it is a rather flammable material by its composition. It is known from the literature that one of the most important steps in protecting wood from fire is fire protection treatment. It is carried out in two main ways: surface treatment (applying special compounds to the wood surface to form a fireproof layer) and deep impregnation of wood with flame retardants. For the fire protection of OSB samples, a water-based intumescent paint consisting of a system of flame retardants in combination with fillers, pigment, and functional additives was developed. The research was conducted using analytical and experimental methods, which consist of analyzing and studying the provisions of national standards that describe the method for determining the flammability group of substances and materials and the method for determining the fire protection efficiency of fire retardants. The experimental part of the study involved the manufacture of test samples, application of fire retardants to them, recording the temperature of gaseous combustion products, the maximum temperature increase, the time interval for reaching the maximum temperature, the weight of the samples, and the weight loss of the samples. The research methodology states that the wood samples were tested in accordance with DSTU 8829 at the OTM installation. It also provides means for measuring the flue gas temperature, test time, and determining the mass loss of samples before and after testing. The test results showed that the developed fire retardant based on intumescent paint provides a group of refractory materials in accordance with DSTU 8829, i.e., the wood protected by this method belongs to refractory materials, namely: the flue gas temperature does not exceed 260˚C, the mass loss of samples after testing is not more than 60%.

OXALIC ACID PRODUCTION OF BANANA PEEL (Musa textilia) THROUGH OPTIMUM TEMPERATURE AND TIME with ALKALINE METHOD


 The chemical compound has the formula H2C2O4 is oxalic acid. Every year especially, the industrial sector in Indonesia requires oxalic acid made, which increases annually. Oxalic acid is valuable because it may be used to clean (rust remover), make colors, protect metals from corrosives, and other things. Alkaline melting is one way for creating oxalic acid from cellulose-containing materials. Other methods include hydrolysis, CaCl2 precipitation, and acidification using H2SO4. In Indonesia, cellulose-containing materials are widely available. Banana peels are one of the substances that contain cellulose. In addition to identifying the properties of oxalic acid produced using the alkaline smelting process, this study attempts to find the best temperature and duration for producing oxalic acid from discarded banana peels. The ideal conditions include a temperature of 60°C, a period of 60 minutes, and a yield of 5.42%. Oxalic acid from banana peel waste has the properties of having a melting point, hydroxyl, C=C, C-O, and C-H group absorption at a wave number of 104.6 oC, 3422.06 cm-1, 1682.48 cm-1, 1103.42 cm-1, and 666.36 cm-1 respectively. Based on the strain vibration results from the FTIR test and melting point test.

Kinetics of biodegradation of strengthening polymer systems based on copolymers of lactic acid and biogenic activators

The production of bioplastics based on copolymers of maleic anhydride with the addition of lactic acid and furyl alcohol is described. The obtained copolymers are promising for use as reinforcing polymer systems of cellulose-containing materials used in packaging. It has been shown that the use of lactic acid and furyl alcohol makes it possible to obtain synthetic bioplastics that are rapidly degradable in natural conditions, which is favorable for environmental protection.

Биопластики на основе сополимеров глицерина, фталевого ангидрида и молочной кислоты

The preparation of bioplastics based on copolymers of maleic anhydride and glycerol with additives of bioactive units of lactic acid is described. The obtained copolymers are promising for the use as reinforcing polymer systems of cellulose-containing materials applied in packaging. It has been shown that the use of lactic acid makes possible to obtain synthetic biopolymers which are rapidly degradable under natural conditions, that is favorable for the protection of the environment.

Cellulose nanofibers reinforced nanocomposites with high strength and toughness by tunable wet-drawing and ionic cross-linking method

Although great achievements have been made for man-made cellulose nanofibers reinforced materials, the toughness is still difficult to be improved due to the stiff nature of cellulose nanofibers. Here, we provide a strategy for molecular and nanoscale engineering of stiff TEMPO oxide cellulose nanofibers (TOCNF) and soft Waterborne Polyurethanes (WPU) macromolecules (30–50 nm) that have strong interactions to form homogeneous and hierarchical compact structures by tunable wet-drawing and ionic cross-linking method. The factors such as R-value (mole ratio of NCO/OH) of WPU, amount of COOH and TOCNF were adjusted to control the inner structure of WPU-TOCNF film. The reorganized and aligned internal structure of WPU-TOCNF caused by external stretch forces increased the mechanical performance greatly. The ionic cross-linking also increased the strength and toughness further. Precisely control the structure of soft WPU macromolecules and ionic cross-linking between soft (WPU) and rigid building blocks (TOCNF) make the strength, extension at break and toughness of the obtained fiber and film reach 715 MPa (323 MPa), 41% (52%), 186 MJ m−3 (110 MJ m−3), respectively. This toughness is the highest among that all the cellulose-containing materials reported so far. Such high toughness for this nanocomposite offers promising potential for functional textile and military aerospace materials in the future.

Multiscale Mechanical Performance of Wood: From Nano- to Macro-Scale across Structure Hierarchy and Size Effects.

This review describes methods and results of studying the mechanical properties of wood at all scales: from nano- to macro-scale. The connection between the mechanical properties of material and its structure at all these levels is explored. It is shown that the existing size effects in the mechanical properties of wood, in a range of the characteristic sizes of the structure of about six orders of magnitude, correspond to the empirical Hall-Petch relation. This “law” was revealed more than 60 years ago in metals and alloys and later in other materials. The nature, as well as the particular type of the size dependences in different classes of materials can vary, but the general trend, “the smaller the stronger”, remains true both for wood and for other cellulose-containing materials. The possible mechanisms of the size effects in wood are being discussed. The correlations between the mechanical and thermophysical properties of wood are described. Several examples are used to demonstrate the possibility to forecast the macromechanical properties of wood by means of contactless thermographic express methods based on measuring temperature diffusivity. The research technique for dendrochronological and dendroclimatological studies by means of the analysis of microhardness and Young’s modulus radial dependences in annual growth rings is described.

INVESTIGATION OF ANTIMICROBIAL PROPERTIES OF TEXTILE MATERIALS AFTER WASHING

This work is devoted to the study of antimicrobial properties of cellulose-containing textile materials treated with new safe biocidal products of thiosulfonate structure. A resource-saving method of providing antimicrobial properties to cellulose-containing textile materials is presented. High antimicrobial activity of biocidal products after washing was established. The duration of action and expediency of their use in the textile industry are proved. It is shown that after 10 washes the treated tissues lose only 14-15% of antimicrobial properties.

FEATURES OF THE PRIMARY PREPARATION OF HEMP STRAW STALKS SUITABLE FOR OBTAINING CELLULOSECONTAINING MATERIALS AND PAPER

The features of the primary preparation of hemp straw stalks suitable for obtaining cellulosecontaining materials and paper are considered in the article. The primary processes of the preparation of hemp raw materials for pulp production, which include harvesting, storage of straw stalks, transportation, and primary processing of raw materials suitable for obtaining cellulose-containing materials, are described. Methods of shortening stems and fibers applied in the pulping process are studied in detail. Technological methods of shortening straw stalks of technical hemp and cleaning raw materials from grains and garbage impurities are mentioned. The necessity of applying the processes of stalks crushing and wet purification of chopped straw stalks of technical hemp is proved.

Фанера и теплоизоляционные плиты на модифицированном фенолоформальдегидном связующем

The lower curing temperature of phenol formaldehyde binder allows reducing the costs of producing cellulose-containing materials, such as FSF plywood and thermal insulation composites made of plant wastes. However, the low-temperature production mode provides an insufficient degree of the phenol formaldehyde binder curing, leading to a decrease in water resistance of material based on the phenol formaldehyde binder. A modifier should be added to the phenol formaldehyde binder to reduce the amount of free hydroxymethylol groups in the cured binder and to form a stronger cross-linked structure in low-temperature curing conditions. Hydrogen peroxide was used as a phenol formaldehyde binder modifier in this research. The research results confirmed the hypothesis about the effect of hydrogen peroxide on the intensification of the structure formation of cellulose-containing materials based on the phenol formaldehyde binder. In conditions of low-temperature curing (120 °C for FSF plywood and 100 °C for thermal insulation composites made of plant wastes) modification of phenol formaldehyde binder with hydrogen peroxide reduced the binder curing time, the pressing time of FSF plywood, improved the physical and mechanical properties of FSF plywood and thermal insulation composites made of cellulose-containing filler (soft wood waste and irrecoverable flax spinning waste). When 1.0 % of hydrogen peroxide is added to the binder, the binder curing time reduces by 43.6 %. The addition of 1.0 % of hydrogen peroxide increased the shear strength of FSF plywood by 4.4 % and the static bending strength of plywood by 4.8 %. Modification of the binder with hydrogen peroxide increased water resistance of FSF plywood: plywood thickness swelling has been reduced by 2 % over 24 h in water. The strength of thermal insulation composites made of cellulose-containing wastes increased by 5.2 % with the addition of 1.0 % of hydrogen peroxide, thickness swelling decreased by 4.9 % over 24 h. The obtained research results allow recommending a modifying additive of hydrogen peroxide to phenol formaldehyde binder in an amount of 1.0 % of resin mass to increase the strength properties of FSF plywood and thermal insulation composites made of plant wastes. For citation: Vakhnina T.N., Fedotov A.A., Susoeva I.V., Rumyantseva V.E. Plywood and Thermal Insulation Boards Based on the Modified Phenol Formaldehyde Binder. Lesnoy Zhurnal [Russian Forestry Journal], 2022, no. 1, pp. 155–165. DOI: 10.37482/0536-1036-2022-1-155-165

Новый подход к использованию льняного отечественного сырья

The conditions for obtaining stable metallic silver hydrosols in the presence of flax fiber extracts have been studied by the method of «green chemistry» and the possibility of using synthesized sols to provide cellulose-containing materials with antimicrobial activity or biosecurity has been proved. The process of synthesis of ultrafine silver particles in the presence of concomitant natural impurities of flax fibers isolated from them during alkaline high-temperature treatment was studied by spectrophotometry, photon correlation spectroscopy and visual observation. The effect of the extract composition on dynamics of the formation of stable silver nanoparticles was determined. IR spectroscopy and potentiometric titration methods proved that an increase in the alkalinity of a cooking solution led not only to an increase in the amount of impurities in the solution, but also to their destruction, and the complex of reducing substances formed in the solution could act as a silver ion reducing agent even at a low extraction temperature. It was proven that antimicrobial activity against test cultures of synthesized sols and cellulose tissue treated with them depended on the conditions of synthesis.

Cellulose-containing waste recycling using fungi

Accumulation of plant waste is a serious environmental problem. Mushrooms with high cellulolytic activity can process it into valuable products that will be useful in solving various industries and agriculture problems. The enzymes of the cellulolytic complex include 1,4-β-D-glucan-4-glucanohydrolase, exo-1,4-β-glucosidase, cellobiohydrolase, β-glucosidase. 1,4-β-D-glucan-4-glucanohydrolases destroy β-1,4-glycosidic bonds within the chain of cellulose and lichenin polysaccharides. Exoglucanases destroy β-1,3- and β-1,4-glycosidic bonds at the end of the molecule. Cellobiohydrolases cleave β-1,4-glycosidic bonds to form cellobiose and glucose. β-glucosidase complete the process of destruction. Fungi with high cellulolytic activity include both representatives of the Ascomycota and Basidiomycota divisions. Ascomycete Chaetomium globosum produces endoglucanases of two families and 8 cellobiohydrolases. Myceliophthora thermophila also produces endoglucanases and cellobiohydrolases, the most abundant of which is Mt Cel7A. The fungus is a promising producer of thermostable enzymes. Trichoderma reesei has a long history of safe use as a source of highly active cellulolytic enzymes and other valuable metabolites. LPMOs of the cellulolytic fungus Thielavia terrestris are considered auxiliary enzymes, but can negatively affect the main enzymes of the complex. Irpex lacteus also produces LPMO and a complete cellulolytic enzyme complex. The cellulolytic activity of fungi and their ability to grow on cheap substrates can be used to bioconvert plant waste into valuable products. One of the ways to utilize them is to convert into compound feed with a high protein content through the use of starter cultures. The use of mushrooms will increase the content of protein and simple carbohydrates, enrich the feed with fats. Another method is to obtain cellulases, which are widely used in many industries. Thanks to the production of biodiesel and bioethanol from cellulose-containing raw materials it is possible to solve the problem of lack of fuel by replacing energy carriers from non-renewable energy sources with their environmentally friendly counterparts. They are less toxic than diesel and gasoline and are also made from renewable resources.

MICROBIAL CULTURES PRODUCING HYDROLYTIC ENZYMES TO BE FURTHER USED IN PROCESSING OF AGRICULTURAL AND FOOD INDUSTRY WASTES

The results of isolation and research of microorganisms – producers of hydrolytic enzymes, biodestructors of cellulose-containing materials, identification of limiting factors for optimizing the processes of biodestruction, ways and prospects of their use for biotechnological processing of biogenic raw materials are presented. A new strategy for the fermentation of cellulose-containing waste in dumps and storage facilities of biogenic waste is proposed. One of the key points of the new technology is the creation of a volumetric zone of active biodegradation using a new type of open-type reactor that creates an optimal environment for the growth of biodegradators. The results of such processing are organic fertilizers, humates, feed protein and other useful products.

X-RAY STRUCTURAL ANALYSIS OF COTTONS AND HERBACEOUS CELLULOSE

It was found that the extrusion treatment of cotton cellulose in an aqueous medium, followed by drying and grinding on a hammer mill leads to a decrease in the crystallite size in the transverse direction ([110] and [100]) as a result of mechanical destruction of cellulose macromolecules, and the subsequent acid hydrolysis of cellulose in H2SO4 solutions to an increase in the size of crystallites in the transverse direction ([110], [110] and [100]) due to co-crystallization processes. It is shown that alkaline cooking of cellulose-containing material, followed by extrusion processing, washing, drying and grinding on a hammer mill leads to an increase in the transverse dimensions of crystallites in the [110] and [100] directions for flax cellulose and in the [110], [110] and [100] – for cellulose from oats and alfalfa as a result of partial removal of lignin and hemicelluloses from the cellulose-containing material.
 Differences were revealed in the sizes of the coherent scattering regions and the parameters of the crystallographic cell of cellulose samples from cotton and herbaceous plants (flax, oats, and alfalfa), as well as between samples from oats and alfalfa obtained under the same conditions with the same type of feedstock (straw).
 It has been established that the proposed stepwise technology for processing cotton and linen fibers leads to a slight decrease in the degree of crystallinity and the average degree of polymerization, which indicates that the developed technology for obtaining high-viscosity powder celluloses for various purposes is promising.
 Correlation coefficients are established between the values of the degree of ordering of the structure of cellulose samples from various plant raw materials, calculated using X-ray diffraction analysis and FT-IR spectroscopy, which make it possible to adequately compare all the known literature and experimental data.