The present study is focused on polylactic acid (PLA) blending with bio nanoadditives, such as Tonsil^® (clay) and Aerosil^®, to obtain nanocomposites for a new generation of food packaging. The basic composition was enhanced using Sorbitan oleate (E494) and Proviplast as plasticizers, increasing the composite samples’ stability and their mechanical strength. Four mixtures were prepared: S1 with Tonsil^®; S2 with Aerosil^®; S3 with Aerosil^® + Proviplast; and S4 with Sabosorb. They were complexly characterized by FT-IR spectroscopy, differential scanning calorimetry, mechanical tests on different temperatures, and absorption of the saline solution. FTIR shows a proper embedding of the filler component into the polymer matrix and DSC presents a good stability at the living body temperature for all prepared samples. Micro and nanostructural aspects were evidenced by SEM and AFM microscopy, revealing that S3 has the most compact and uniform filler distribution and S4 has the most irregular one. Thus, S3 evidenced the best diametral tensile strength and S4 evidenced the weakest values. All samples present the best bending strength at 18 °C and fair values at 4 °C, with the best values being obtained for the S1 sample and the worst for S4. The lack of mechanical strength of the S4 sample is compensated by its best resistance at liquid penetration, while S1 is more affected by the liquid infiltrations. Finally, results show that PLA composites are suitable for biodegradable and disposable food packages, and the desired properties could be achieved by proper adjustment of the filler proportions.

Composites based on polylactic acid (PLA) and copper for food packaging applications were obtained. Copper clusters were synthesized in polyethylene glycols 400 and 600, respectively, using ascorbic acid as a reducing agent, by reactive milling. Copper clusters were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FT-IR), and Ultraviolet-Visible (UV-VIS) spectroscopy. Copper/PLA composites containing Proviplast as plasticizer were characterized by FT-IR spectroscopy, mechanical tests, Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), absorption of the saline solution, contact angle, and antibacterial properties. It was observed that the concentration of Copper/PEG influenced the investigated properties. The mechanical properties of the samples decreased with the increasing of Copper/PEG concentration. We recorded the phase transformation temperatures and identified the exothermic or endothermic processes. The lowest absorption values were recorded in the case of the sample containing 1% Cu. The contact angle decreases with the increase in the concentration of the PEG 600-Cu mixture in the recipes. The increase in the content of Cu clusters favors the decrease in the temperature, taking place 15% wt mass losses. The obtained composites showed antibacterial properties for all tested strains. These materials could be used as alternative materials for obtaining biodegradable food packaging.

This study focuses on the development of bioactive packaging materials by incorporating grape pomace and copper particles into polylactic acid (PLA) composites. The goal is to increase the shelf life of packaged foods while benefiting the health of consumers through the use of these active materials. 6 recipes of composite materials based on polylactic acid and Proviplast 2624 plasticizer were obtained. The additives added were: grape pomace, added at 0.5%, 1% and 1.5%, and copper particles, formed using PEG 600 + CuSO₄, added at 2%, 5% and 8%. Material characterization techniques: FTIR Spectroscopy, used to study the chemical structure. Differential scanning calorimetry (DSC): examined thermal transitions such as glass transition and melting temperatures. Thermogravimetric analysis (TGA) and differential thermogravimetry (DTG): evaluated thermal stability and degradation temperatures. Scanning electron microscopy (SEM) and atomic force microscopy (AFM): analyzed the surface morphology and structure. Mechanical tests: evaluated tensile strength, elongation at break and flexibility. Thermal property analyzes revealed that the additives acted as plasticizers, reducing the intermolecular forces between PLA chains, which decreased the glass transition temperature (Tg), cold crystallization temperature (Tcc) and melting temperature (Tm). The addition of grape pomace and copper particles decreased the degradation temperature of PLA composites, indicating a slight reduction in thermal stability. The transformation temperatures changed and the nature of the thermal transitions (exothermic or endothermic) varied with additive concentrations. Mechanical properties indicated a reduction in tensile strength with increasing additive concentration. Elongation at break and longitudinal modulus of elasticity increased significantly, especially with grape pomace, improving the flexibility of PLA. These changes indicate that the material can absorb more energy before breaking, making it more ductile and more suitable for flexible packaging applications. Increased flexibility and improved thermal resistance ensure that these materials can withstand the demands of packaging, handling and shipping. The combination of improved flexibility, thermal resistance and moderate tensile strength makes these PLA-based composites incorporated with grape pomace or copper particles, enhance the aspect of sustainability by recycling agricultural waste, making the material both ecological and functional, making it a viable option for active food packaging.

Poly(lactic acid) (PLA) is a biodegradable thermoplastic polymer used in various applications, including food packaging, 3D printing, textiles, and biomedical devices. Nevertheless, it presents several limitations, such as high hydrophobicity, low gas barrier properties, UV sensitivity, and brittleness. To overcome this issue, in this study, biochar (BC) produced through pyrolysis of bio-mass waste was incorporated (1 wt.%, 2wt.%, and 3 wt.%—PLA 1, PLA 2, and PLA 3) to enhance thermal and mechanical properties of PLA composites. The impact of pyrolysis temperature on the kinetic parameters, physicochemical characteristics, and structural properties of banana and orange peels for use as biochar added to PLA was investigated. The biomass waste such as banana and orange peels were characterized by proximal analysis and thermogravimetric analysis (TGA); meanwhile, the PLA composites were characterized by tensile straight, TGA, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results indicated that the presence of biochar improved hygroscopic characteristics and Tg temperature from 62.98 °C for 1 wt.% to 80.29 °C for 3 wt.%. Additionally, it was found that the tensile strength of the composites increased by almost 30% for PLA 3 compared with PLA 1. The Young’s modulus also increased from 194.334 MPa for PLA1 to 388.314 MPa for PLA3. However, the elongation decreased from 14.179 (PLA 1) to 7.240 mm (PLA3), and the maximum thermal degradation temperature shifted to lower temperatures ranging from 366 °C for PLA-1 to 345 °C for PLA-3 samples, respectively. From surface analysis, it was observed that the surface of these samples was relatively smooth, but small microcluster BC aggregates were visible, especially for the PLA 3 composite. In conclusion, the incorporation of biochar into PLA is a promising method for enhancing material performance while maintaining environmental sustainability by recycling biomass waste.

This study examines a catalyst based on graphitic carbon nitride (g-C₃N₄) for synthesizing glycerol carbonate through the coupling reaction of glycerol and CO₂. In this research, we focus on simultaneously improving CO₂ emission reduction and glycerol valorization by co-doping g-C₃N₄ with phosphorus (P), sulfur (S), magnesium (Mg), and lithium (Li) for a better catalytic performance. The catalysts were prepared through a one-step thermal condensation process and characterized using XRD, SEM, TGA, FTIR, and nitrogen adsorption–desorption techniques. The co-doping further enhanced the surface chemical properties, Lewis acidity, basicity, and thermal stability, evidenced by the lower crystallinity, wider pore, and better catalytic performance as assessed through glycerol carbonylation reaction, optimized using a Box–Behnken design. The MgPSCN catalyst exhibited the highest glycerol conversion (68.72%) and glycerol carbonate yield (44.90%) at 250 °C, using 50 mg catalyst and 10 bar pressure. The model accuracy was validated by ANOVA (R² > 0.99; p values < 0.0001). The results indicated that doping significantly enhanced the catalytic performance, most likely due to improved electron charge transfer and structural distortions within the g-C₃N₄ framework. Such a process highlights the potential of co-doped g-C₃N₄ catalysts for the sustainable glycerol utilization and valorization of CO₂ through a scalable pathway toward green chemical synthesis—an approach that comes in line with worldwide decarbonization goals.

Biochar activation is achieved by removing tar formed in the pores during the thermal treatment of biomass, thereby increasing pore volume. This process typically involves entraining tar with steam at elevated temperatures for extended durations. In this study, a reduction in lignin content in grape seeds through partial solubilization, prior to thermal treatment, is proposed. Initially, grape seeds were treated with a basic sodium sulfide solution, followed by conditioning with either phosphoric acid or zinc chloride and then drying and calcination. The synthesized adsorbents were characterized using scanning electron microscopy (SEM), textural analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and evaluation of toluene adsorption capacity. Textural analysis indicated that conditioning with phosphoric acid or zinc chloride increased the specific surface area of biochar by over 20%, with a higher increase observed for phosphoric acid treatment. The toluene adsorption capacity of the adsorbents was assessed in a continuous fixed-bed system. Biochar pretreated with ZnCl₂ exhibited an adsorption capacity of 0.11 cm³ of toluene per gram, while biochar pretreated with phosphoric acid demonstrated a capacity of 0.14 cm³ per gram. These results indicate that preliminary delignification of grape seed biomass maintains its adsorption capacity of toluene at levels comparable to other adsorbents, despite a lower activation temperature.