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.

The growing focus on sustainability, eco-friendly technologies, decarbonization, and reducing carbon footprints shapes current industry challenges. This article reviews the potential of cinnamon as a bio-additive for polymer stabilization in packaging. Samples were prepared from ethylene-norbornene copolymer (Topas), a cyclic olefin copolymer known for purity, transparency, and low gas permeability, and poly(lactic acid) (PLA), a bio-based alternative to petroleum plastics. Cinnamon powder was added in 0.5, 1.0, and 1.5 wt%. After solar and thermo-oxidative aging, hydrophobicity, chemical composition, mechanical, and color properties were analyzed. Results showed higher hydrophobicity and resistance to hydrolytic degradation due to reduced water penetration. PLA, normally brittle, became more flexible, with 0.5 wt% cinnamon showing optimal performance after 100 h of solar aging, similar to Topas composites. Overall, PLA and cyclic olefin copolymer (COC) films with cinnamon improved durability, extended food shelf life, and acted as natural color indicators of material aging.

The current experimental investigation presents a comparative evaluation of selected biodegradable polymer blends and their composites, focusing on their material properties. Two biopolymers, polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT), along with pineapple fibers (F), as bio-reinforcement were taken for the analysis, which was conducted in two stages: During first stage, PBAT was melt-blended with PLA in varying weight fractions (10, 20, 30, 40, and 50 wt%) to produce PLA/PBAT blend (B) and in second stage, PLA, PBAT, B 80/20 blend were reinforced with pineapple fiber (10, 20, and 30 wt%). The samples were fabricated using extrusion-injection molding. The samples were characterized for density, thermal degradation, crystallinity, and mechanical behaviour. Among the blends, the optimal B 80/20 combination exhibited tensile strength, flexural strength, and elongation at break of 47.9±2.4, 88.2±5.4 MPa, and 330.6±10.47%, respectively. Results indicate that the PLA-based composites (PF) exhibit significantly better density, tensile strength, and flexural strength as compared to neat polymers, blends, blend-based composites (BF), and PBAT-based composites (TF). Among the PF composites, the PF 70/30 composite demonstrated superior performance, with maximum tensile and flexural strength values of 73.9±1.3 and 107.1±4.3 MPa, respectively.