Structuring liquid oils into oleogels using natural and abundant biomass components as gelling agents is of great significance in fields such as foods, pharmaceuticals, and cosmetics. In this work, a more energy-efficient and technologically simpler approach for directly preparing birch outer bark extract particles containing oleogel was used. This method involves introducing birch outer bark extract particles into the oil phase directly from the extract solution, combining both the evaporation of solution and gel formation. As a result, stable oleogels of various vegetable oils (sunflower, almond, olive, and hemp seed) were obtained with birch outer bark extract particle contents of 4–10%. Infrared spectroscopy and particle size analysis confirmed that when increasing the content of extract particles in the oil, increasing self-assembly of extract particles via hydrogen bonding occurs, leading to the formation of a more structured network. This is consistent with gel strength values from rheological tests of oleogels, which also increased with particle concentration. The obtained oleogels showed important properties such as good tolerance to time-dependent deformation, shear thinning, and thermoreversibility.

Human activities undoubtedly increase greenhouse gases (GHG), negatively influencing global climate change. The building and construction sector uses at least 40% of the total energy consumption and produces the same percentage of GHG emissions. Therefore, the development of sustainable building materials is a crucial key factor for environmental protection. The study contributes to the development of bio-based façade materials using available raw biomass like wheat straw, grey alder, and softwood (a mix of spruce and pine), to promote reduced emissions of CO₂. Two technologies were used to produce high-density particleboards based on (1) steam explosion treatment and (2) the addition of bio-based suberinic acids as a binder. In addition to the biomass species and board type, the influence of conventional and mold hot-pressing was investigated on produced board properties: density, thickness swelling, modules of rupture and elasticity in bending, and internal bonding. The obtained particleboards demonstrate significant differences in terms of the tested properties depending on all variable factors. The best performance, in terms of physical–mechanical properties, was achieved by the conventionally hot-pressed board of steam-exploded grey alder particles, being influenced by the highest density (1380 kg/m³). Mold hot-pressing in most cases resulted in decreased performance of obtained boards.

Birch outer bark (BOB) from Betula pendula Roth. is a unique and valuable biomass feedstock that contains suberin. The biopolyester suberin is built from bifunctional fatty acids-suberinic acids (SA)-which can be obtained thr... | Find, read and cite all the research you need on Tech Science Press

Suberinic acids (SA) derived from birch outer bark are renewable feedstocks for bio-based polyols suitable for rigid polyurethane (PU) foams. Three SA fractions were prepared under different depolymerization conditions: acidification at pH 1 (SA1), pH 5 (SA2), and FeCl₃-assisted treatment (SA3), and their chemical composition was analysed by GC–MS, Py–GC/MS, and GPC–RID. Polyols derived from tall oil fatty acids (TOFA) or epoxidized TOFA with trimethylolpropane were used as the sole polyol components in foam formulations. The SA fractions differed in molecular weight distribution, affecting polyol processability. All foams exhibited similar limiting oxygen index (19–20) and cone calorimetry results, showing no statistically significant differences in flammability. This indicates that variations in depolymerization conditions, including polyphenolic content and removal of higher-molecular-weight fractions during FeCl₃ treatment, do not dominate fire performance under the studied conditions. SA3-based polyols showed the lowest viscosity and produced foams with optimal mechanical and thermal properties, while SA1 offered higher yield with comparable performance. These results demonstrate the feasibility of converting SA fractions into functional polyols for rigid PU foams and highlight the FeCl₃-treated SA3 fraction and SA1 as the most promising candidates for further development.

To improve the extrusion processing of wood–plastic composites (WPCs), functional additives known as internal lubricants are incorporated into the composite formulations. The lubricants play a crucial role in decreasing the melt viscosity of WPCs, which in turn has a positive impact on energy consumption, productivity, and overall composite performance. This study shows the effect of suberinic acids (SAs), extracted from birch outer bark via alkaline water and water–ethanol hydrolysis at different pH values, on the processing behavior and properties of a recycled polypropylene-based composite filled with pine microfibers. The extracted SAs were characterized by gas chromatography–mass spectrometry, Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry. The conducted analyses revealed notable differences in the chemical composition, molecular weight, and molecular polydispersity of the SAs. Betulin was identified as the dominant component (49–86%). The pine sawdust was treated with 2% NaOH at 90 °C for 90 min prior to composite fabrication. The incorporation of 4.0 wt% SAs into the WPC formulations reduced the extruder rotor’s maximum and minimum torques torque, indicating improved processability of the composite. Mechanical and wetting properties of the WPC samples were evaluated. The samples containing SAs exhibited an increased elongation at break by 37.9–51.6% and bending deformation by 12.8–17.5%, depending on the extraction conditions of SAs, accompanied by a slight reduction in the mechanical properties and slight increase in water sorption compared with the composite filled with the alkaline-treated pine microfibers. The results showed enhanced flexibility and ductility in the SAs-containing WPCs. The presence of a 1.0 wt% maleic anhydride-grafted polypropylene in the samples led to an increase their mechanical properties, along with the reduced water sorption.

This study focuses on the development of wood-based particleboard that address resource efficiency, environmental sustainability, and health-related concerns. The conventional particleboard industry relies on synthetic, predominantly formaldehyde-based adhesives, which pose environmental, health, and end-use risks. Rising raw material prices, regulatory restrictions, and increasing competition in the wood-processing sector have further highlighted the importance of alternative biomass resources for particleboard production. In response to these challenges, this study investigates the suitability of available sawdust resources derived from the production residues of cellular wood materials and recycled particleboards, combined with natural suberinic acids mixture obtained from birch outer bark as a binder. The effects of furnish structure, binder content (15–21%), pressing temperature (190–220 °C), pressing rate (0.9–1.7 min/mm), and board density (650–850 kg/m³) on the resulting particleboard properties were evaluated. The results demonstrate that it is possible to meet the requirement values for thickness swelling (≤17%) and internal bonding strength (≥0.40 N/mm²) specified for interior fitment boards, including furniture applications according to EN 312, Type P2. The bending properties of the best-performing particleboards are very close to the requirement values (MOE ≥ 1800 N/mm², MOR ≥ 11 N/mm²), indicating the potential for further improvement at the target density range. Furnish structure, board thickness, density, and pressing temperature were identified as the most influential factors affecting the final board properties.