FUNCTIONAL MATERIALS FROM WASTE PAPER. III. COMPARATIVE STUDY OF MORPHOLOGY OF POWDER CELLULOSES AND CELLULOSE HYDROGELS

The morphology of hydrogels regenerated from solutions of waste paper and cardboard in DMAс/LiCl was studied for the first time in comparison with the morphology of pristine samples and powder celluloses isolated from waste paper. Two sets consisted every of them from 4 samples, pristine waste paper or cardboard, powder cellulose, swollen hydrogel and freeze-dried hydrogel, were examined with a SEM. As revealed by SEM, the freeze-dried hydrogels are porous systems with a variety of through pores in a wide range of sizes. The number, shape, and size of pores, as well as their availability, differed markedly. The pore sizes in freeze-dried hydrogels obtained from the waste paper are mostly ranged at 30-50 nm. The smallest pores in the waste cardboard are 30-40 nm in size, the largest ones are up to 4 μm. According to the results of the study, these samples will have satisfactory sorption properties but, due to the different morphology of the porous system, the availability of each sample is likely to vary significantly.

Virucidal activity of Nasaleze Cold® & Flu Blocker and Nasaleze® Travel in cell cultures infected with human pathogenic coronavirus 229-E

This in vitro study determined the anti-viral efficacy of a unique blend of powder cellulose supplemented with powdered garlic extract (PGE) and a signalling agent. The composition, presented as Nasaleze Cold & Flu Blocker/Nasaleze Travel, was assessed against Human Coronavirus 229E, CoV 229E {ATCC VR-740} in an in vitro experiment. The test substance was used at sub-optimal dosing levels to explore its prevention and treatment capabilities. The virucidal activity of this novel formulation was measured at 48, 72 and 112 hour periods after incubation. Results showed strong reductions in viral titre of Coronavirus 229E compared to a control, while no toxicity to human cells from the test formulation was noted. The extract Nasaleze Cold/Travel showed potential to be used as a therapeutic and preventive agent. The data reconfirms the established anti-viral activity of this formulation acting as a barrier preventing the virus from accessing the nasal mucosa and disrupting its replication.

"PALLADIUM ON COAL" CATALYST OBTAINED BY PYROLYSIS OF POWDER CELLULOSE GRANULES IM-PREGNATED WITH PALLADIUM NITRATE

By pyrolysis of powdered cellulose granules impregnated with palladium nitrate, catalysts of 1–8% Pd / C were obtained. Pyrolysis was carried out in a reactor with a water seal at 600 ° C. Metal reduction was carried out with pyrolysis gases and matrix carbon. It was found that the ash content of powdered cellulose granules is ~ 40 times less than the ash content of sulfate cellulose, from which they were made. It was shown by X-ray phase analysis and electron microscopy that palladium in the catalysts is present in the form of Pd (0) nanoparticles uniformly covering carbon fibers and shapeless massive metal precipitates up to 20 μm in diameter. In catalysts 1–3% Pd / С, nanoparticles 10–40 nm dominate (> 95%), in 8% Pd / С, 20–70 nm. The share of massive metal formations in Pd (1%) / C, Pd (3%) / C and Pd (8%) / C is: ~ 2%, ~ 5% and ~ 60%, respectively. They consist of aggregated spherical particles 0.05–0.15 µm in diameter. XRD palladium oxide was not detected in the catalysts. The presence of palladium nitrate in powdered cellulose during its carbonization has a significant effect on the formation of the carbon matrix. With an increase in the content of palladium nitrate in powdered cellulose, the yield of carbon material decreases and its total porosity increases. Infrared spectroscopy revealed the presence of oxygen-containing ether groups in the carbon matrix of palladium catalysts. The activity of catalysts in the model process of decomposition of hydrogen peroxide increases with increasing dispersion of palladium nanoparticles.

HYDROPHILIC RUBBER BASED ON BUTADIENE-NITRILE RUBBER AND POWDER CELLULOSE OF PLANT ORIGIN

It has been established that the introduction of powdered cellulose, obtained by chemo-mechanical destruction from oat straw, into the composition of rubbers as a hydrosorption filler increases the conditional tensile strength of vulcanizates in comparison with samples without this filler. It was revealed that the degree of swelling of rubbers containing powdered cellulose from oat straw, the pH of the aqueous medium and the degree of mineralization have little effect.

THE INFLUENCE OF THE KNIFE METHOD OF GRINDING PULP ON THE PROCESS OF OBTAINING POWDERED CELLULOSE

This article presents the classification of the resulting types of powdered cellulosic materials, their scope, as well as the problems arising during production. The main properties of powder cellulose materials are considered. Analyzed the quality indicators of the pulp, previously ground in a disc mill. The main technological parameters of the experimental setup and the comparative characteristics of the used knife grinding sets are presented. In the course of the experimental research, knife grinding sets with straight and curved knives were used. The data obtained confirmed the previously put forward hypothesis about the predominant fibrillation of cellulose fiber milled using a grinding set with a curved blade shape. This feature of the headset design is especially important when grinding hardwood pulp, which has a lower initial value, compared to softwood pulp. The data obtained in determining the degree of grinding, water retention capacity, fiber length of softwood and hardwood cellulose after knife grinding and the degree of polymerization after hydrolysis are presented. A method for producing powdered cellulose material with characteristics similar to microcrystalline cellulose is considered. The regulated parameters of the hydrolysis process are set and a comparison is made of the degree of polymerization of the considered samples of powdered cellulose.

INFLUENCE OF THE FIBROUS MASS GRINDING METHOD ON THE PROCESS OF POWDER CELLULOSE PRODUCTION

The article presents results of experimental studies of cellulose properties depending on different shaped knife tooling of the disk mill used for grinding. A method for production of powdered cellulose material with characteristics close to microcrystalline cellulose is considered.

Thermal characteristics of birch and its cellulose and hemicelluloses isolated by alkaline solution

Cellulose and hemicelluloses were isolated from birch wood using a dilute alkaline solution and then consolidated into pellets as model compounds of cellulose and hemicelluloses in the wood cell wall. The purity of isolated cellulose and hemicelluloses was examined by Fourier-transform infrared spectroscopy and thermogravimetric analysis. The density, thermal diffusivity, heat capacity, and thermal conductivity were experimentally determined for consolidated birch powder, cellulose, and hemicelluloses in over-dry condition. The thermal degradation kinetic parameters of these materials were successfully calculated using a conversion rate step of 0.01, and the relationship with conversion rate was established. The results show that cellulose and hemicelluloses consolidated under 25 MPa had densities of 1362 kg/m3 and 1464 kg/m3, respectively. The cell wall of birch powder in the oven-dry state was not collapsed under 25 MPa. The thermal diffusivity of consolidated birch powder, cellulose, and hemicelluloses linearly decreased with temperature, with values of 0.08, 0.15, and 0.20 mm2/s at room temperature, respectively. The specific heat capacity (1104, 1209, and 1305 J/(kg·K) at 22 °C, respectively) and thermal conductivity (0.09, 0.24, and 0.38 W/(m·K) at 22 °C, respectively) linearly increased with temperature, except for those for hemicelluloses which exhibited a nonlinear relationship with temperature above 120 °C, and their linear experimental prediction equations were given. Birch cellulose was more thermally stable than hemicelluloses. The thermal degradation kinetic parameters including activation energy and pre-exponential factor of birch powder, cellulose, and hemicelluloses varied with the conversion rate and calculation methods, with average activation energy in a conversion rate range of 0.02–0.15 of 123.2, 159.0, and 147.2 kJ/mol, respectively (using the Flynn–Wall–Ozawa method), for average natural logarithm pre-exponential factors of 25.0, 33.1, and 28.7 min−1, respectively. Linear and quadratic equations were fitted to describe the relationship between the kinetic parameters and conversion rates. These results give comprehensive thermal properties of the densified cellulose and hemicelluloses isolated from a specific wood.

Low And Highly Substituted Carboxymethyl Cellulose Synthesis From Powdered And Microcrystalline Cellulose

The conditions for low and highly substituted water-soluble carboxymethyl cellulose synthesis based on microcrystalline and powder cellulose by the suspension method have been investigated. Accordingly, it was obtained CMC water-soluble samples with 0.38-0.40 substitution degree based on microcrystalline and powder cellulose. And at one stage, there were obtained CMC samples with a high degree of substitution (1.4) by carboxymethylation so called polyanionic cellulose.

Research of Physical and Chemical Properties of Powder Cellulose from Various Type of Raw Materials

The features of obtaining powder cellulose from non-woody plant materials, excluding the stages of acid and / or enzymatic hydrolysis using the original technological approach at atmospheric pressure and temperature, were studied 90-100 degree of Celsius. The feedstock after alkaline treatment, according to the proposed technology, is subjected to physico-chemical activation using a modified extrusion unit, providing intensive grinding and defibrillation of the fibers, washing, drying, grinding on a hammer mill. Physicochemical and structural studies of the obtained powder pulp from lucerne, oat straw and cotton powder pulp were carried out. The efficiency and prospects of the proposed process are shown.