We have discovered that water-insoluble proteins (IM) isolated from whole soy meal (WM) have the capacity to improve the thermal stability of polypropylene (PP) wood composites without negatively impacting mechanical properties. We compared an undiluted composite to composites diluted with 5% by weight of a 3/1 w/w mixture of stearic acid and paraffin wax (SA/wax), 5% by weight IM, 5% by weight WM, 5% by weight of a 50/50 w/w mixture of IM in combination with SA/wax, and 5% by weight WM in combination with SA/wax. Water contact angle (CA) measurements and Fourier transform infrared spectroscopy (FTIR) revealed a synergy between IM and SA/wax, resulting in enhanced surface hydro - phobicity. Thermogravimetric analysis (TGA) showed lower weight loss in composites made with IM up to the onset of the degradation of PP, and reduced rates of lignin degradation, independently of the presence of SA/wax. Dynamic mechanical analysis (DMA) revealed higher modulus and lower viscoelastic loss resulting from the removal of water-soluble soy components from WM. Total reflectance ultraviolet spectroscopy (UV) showed that IM absorbs UV radiation strongly in the UV-B and UV-C regions. Collectively, these findings suggest that IM has the potential to become a multi-purpose additive for use in PP wood composites.

This is an editorial article. It has no abstract.

We investigated the effectiveness of plant-based bio-additives – rhubarb, lingonberry, and blueberry (0.1–1%) – as natural UV absorbers in biodegradable polymers polylactide (PLA) and polycaprolactone (PCL). A novelty of this work is the direct use of plant-based raw materials as UV absorbers in polymers. We performed Fourier transformed infrared spectroscopy (FT-IR) and UV-Vis analysis of the bio-additives, determined the ultraviolet protection factor (UPF) for the polymer samples, and evaluated their physicochemical properties (structural changes, colour, hardness, surface energy) after weathering (PLA) and thermo-oxidative (PCL) aging. Spectroscopic tests confirmed the presence of UV-A/UV-B-absorbing chromophores in the additives. Samples with 1% berries had excellent UV protection (UPF 40–50+), while PLA and PCL containing 1% rhubarb had lower UPF values (around 22), indicating good UV blocking properties. After aging, PLA-containing berries showed a significantly lower carbonyl index (CI), indicating reduced photodegradation. For PCL with lingonberry, this additive gave the greatest reduction in thermo-oxidative degradation (lowest CI). All plant additives increased material hardness by acting as nucleating agents; they increased the crystallinity of polyester, and aging further strengthened this effect. Bio-additives, especially berries, can increase the hardness and UV resistance of polymers and limit material aging. These polymer compositions are suitable for packaging materials.

This study investigates the structure–property relationships of multi-functional urethane acrylate resins designed as photoreactive binders for UV-curable nail coatings. Four systems were examined: a commercial resin urethane dimethacrylate (UDMA), a bio-based acrylated epoxidized soybean oil (AESO), and two newly synthesized bio-based urethane acrylates derived from 1,3-propanediol (PDO–UA) and eugenol (EUG–UA). Photopolymerization kinetics were analyzed by realtime FTIR, while the properties of the cured coatings were also determined. The mechanical and thermal behavior of selfsupporting polymer films was evaluated by tensile testing and DSC analysis. The UDMA network exhibited the highest crosslink density, reflected in its high modulus (≈0.5 GPa), tensile strength (≈15 MPa), and Tg (≈60°C), making it suitable for use as a top coat. AESO showed moderate stiffness and flexibility, whereas PDO–UA and EUG–UA formed soft, low-Tg (–12 and –17°C) and highly deformable networks typical of elastomeric materials. The combined mechanical and thermal results confirmed that crosslink density strongly governs coating performance and applicability. This study demonstrates that blending UDMA with bio-based oligomers enables the design of sustainable, UV-curable nail lacquers with an optimal balance of hardness, flexibility, and adhesion to the natural nail plate.

This study investigates the interaction between poly(butylene adipate-co-terephthalate) (PBAT) and amber powdered waste (AbW) from jewelry at different filler concentrations (0, 1, 2.5, and 5 wt%) obtained via melt mixing in a corotating twin screw extruder. The resulting materials were pelletized and processed using two techniques: 1) cast film extrusion and 2) injection molding. The shaped specimens exhibited excellent interfacial adhesion. Thermal behavior, as assessed by Vicat softening temperature (VST), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA), showed minimal variation among the composites. Despite similar melt flow rate (MFR) values among the samples, the incorporation of AbW affected the behavior of the polymer during cast film extrusion. Consequently, the composite films exhibited lower tensile mechanical parameters (tensile strength, Young’s modulus, stress and strain at break) compared to the neat PBAT film. In turn, the injection molded composites showed improved tensile, flexural, and impact parameters compared to their neat counterpart. Additionally, a slight decrease in water contact angle (WCA) suggested increased surface hydrophilicity of the extruded films. These findings demonstrate the potential of AbW as an additive for biopolymer composites with enhanced mechanical performance. The increased surface hydrophilicity is particularly relevant for applications targeting biocompatibility and biodegradability.