The objective of this study was to investigate the chemical composition of the obtained products, as well as the antioxidant activity and bio-stimulant potential of the liquid fractions. The biomass was subjected to pyrolysis in a pilot-scale reactor, followed by distillation of the pyroligneous liquid to separate volatile compounds and enrich bioactive fractions. The samples were analysed by FTIR, TGA/DTG, and GC-MS. Antioxidant activities were assessed through DPPH, FRAP, and total phenolic content assays, while the bio-stimulant potential was evaluated through germination and growth tests of lettuce and arugula seeds. The results showed that the distilled fraction had lower acidity, greater chemical stability, and high antioxidant activity, with the presence of industrially valuable compounds such as methoxylated phenols and furfural. Furthermore, application of the distilled liquid at 0.1% concentration stimulated early seedling development—especially in arugula—while higher concentrations demonstrated inhibitory effects. These findings show that distillation of pyroligneous liquid is an effective strategy to enhance its bioactive properties, enabling its use as a natural antioxidant and plant bio-stimulant.
Prepregs are commonly fabricated with non-renewable petroleum-based materials. To reduce the impact of the manufacturing of these materials and to produce more sustainable prepregs, this research aims to manufacture poly(furfuryl alcohol)/wood veneer prepregs and their posterior molding in laminate composites. For this purpose, the vacuum infusion process was used to impregnate the wood veneers, and compression molding was applied to manufacture three- and four-layer laminate composites. Scanning electronic microscopy was used to evaluate the impregnation. the laminate manufacturing and differential scanning calorimetry were used to predict the shelf-life of the prepregs, Fourier-transform infrared was used to evaluate the induced hydrolysis resistance, and thermogravimetric analysis was used to determine the thermal degradation of the laminates. Moreover, water uptake and flexural, compressive, and tensile properties were evaluated. The kinetic models were effective and showed a shelf life for the laminates of approximately 30 days in storage at −7 °C, which is an interesting result for laminates with lignocellulosic materials. FTIR proved the laminates’ excellent resistance to hydrolysis. The water absorption, thermal stability, and mechanical properties did not differ as the amount of wood veneer increased, but these results were up to ~40% higher compared with unidirectional wood laminates found in the literature, which is probably linked to the excellent interface observed with SEM.
6 August 2025 in European Journal of Wood and Wood Products
In this study, hybrid materials were synthesized incorporating curcumin, Cu²⁺ or Fe³⁺, and Kappa-carrageenan as a reducing agent to improve its stability, considering that curcumin has low thermal and solution stability, which limits its applications. Colorimetric analysis showed color changes in the hybrids, ultraviolet-visible spectroscopy revealed band shifts in the hybrids, and infrared analysis indicated shifts in wavenumbers, suggesting changes in the vibrational state of curcumin after bonding with metal ions. These techniques confirmed the formation of the hybrid materials. Thermogravimetric and chromatographic analyses demonstrated greater thermal and solution stability for the hybrids compared to curcumin. Additionally, the hybrid composites effectively developed natural and sebaceous latent fingerprints with good clarity and contrast on glass surfaces. Both composites performed similarly to commercial gold powder. When applied to surfaces representative of forensic scenarios, the composites were versatile, revealing sufficient fingerprint details for human identification on both porous and non-porous surfaces. Scanning electron microscopy images showed greater clarity in sebaceous and natural fingerprints developed with the Fe composite compared to the Cu composite, due to minimal interaction of Fe with the glass surface.
Arundo donax L. is a plant with great potential as lignocellulosic biomass, being a promising source for the development of biodegradable materials. This study evaluated the effects of different chemical pretreatments (H2SO4, NaOH, and NaClO) combined with dry milling on the physicochemical properties of biomass. Pretreatment with NaClO was the most effective in removing lignin, reducing its content to 0.2%, while increasing the cellulose content to 67%. Pretreatment with H2SO4, although retaining a higher lignin content (24%), resulted in the greatest reduction in particle size, reaching a mean diameter (Dm) of 44.31 µm after 20 h of milling. Density analysis revealed that the raw samples reached a maximum density of 0.218 g/cm3 after 20 h of milling, with the pretreated samples showing lower densities due to the removal of structural components. Thermal analysis showed mass losses of up to 66.4% for samples pretreated with NaClO after 10 h of milling, indicating significant structural changes and improved thermal stability. Morphological analysis via SEM demonstrated elongated and fine particles, with acid pretreatment resulting in the most pronounced structural changes. These findings highlight the efficiency of combining chemical and physical pretreatments to modify the structure of A. donax L., optimizing its properties for the production of high-performance biodegradable materials.