The production of tomatoes faces significant challenges, including the high amount of waste generated during the harvest stage and copper-contaminated soil due to pesticide use. To address these issues and to promote a more sustainable agriculture, innovative biodegradable green composites for contextual controlled soil fertilization and Cu removal were produced by 3D-printing technology. These composites were made by incorporating NPK fertilizer flour and tomato plant waste particles (SLP) into three different biodegradable polymeric matrices: polylactic acid (PLA); a commercial blend of biodegradable co-polyesters (Mater-Bi (R), MB) and their blend (MB/PLA, 50:50). Rheological characterization suggested the potential processability of all of the composites by FDM. Morphological analysis of printed samples confirmed the good dispersion of both filler and fertilizer, which also acted as reinforcement for MB and MB/PLA composites. SLP and NPK moduli were evaluated by powder nanoindentation and, for almost composites, the theoretical Halpin-Tsai model satisfactorily fitted the actual tensile moduli. The decrease in NPK fertilizer release rate and the increase in Cu(II) removal efficiency were achieved using whole 3D-printed composites. By selecting the appropriate matrix and incorporating SLP particles, it was possible to tune the NPK release rate and achieve copper absorption efficiency. Notably, MB samples containing SLP particles displayed the fastest release and the highest Cu(II) removal efficiency.

This research aims to develop an environment-friendly composite material that possesses enhanced fire retardant (FR), thermal, as well as mechanical characteristics. The aim has been accomplished with the development of a jute/thermoplastic starch (TPS) based bio-composite. The fire retardancy and thermal stability of the jute/TPS composite were enhanced by the incorporation of magnesium carbonate hydroxide pentahydrate (MCHPH). Upon exposure to heat or fire, the MCHPH particles decompose in a two-stage process to yield water vapors and a char layer of MgO and CO2, which restrict access to oxygen and result in flame suppression. Moreover, the main contribution of the article is the improvement of mechanical properties simultaneously with the enhancement in the fire retardant and thermal properties, which have rarely been reported in the literature. The enhancement of mechanical properties is supported by the compatibility of MCHPH particles with jute/TPS. All the composites were developed with a constant 40 % jute fiber content, while the MCHPH concentration varied from 0 % to 9 % by weight. The tensile strength of TPS was enhanced by 595 % with the reinforcement of jute fiber and MCHPH nano-filler. Compatibility between TPS, jute, and MCHPH was discovered through Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) was used to study the fractured surfaces of the composites. Thermo-gravimetric analysis (TGA) revealed a decrease in the weight loss of the MCHPH-filled jute/ TPS composites at high temperatures. The vertical burning test also revealed that the composites met the re-quirements for a V-0 rating. The heat release rate of the composites was reduced by 36 % after the addition of MCHPH, as measured by cone calorimetry test. The biodegradability test confirmed the eco-friendly nature of the composites by demonstrating significant weight loss in soil over a 4-weeks period. Thus, the present study provided the basis for the development of a novel green composite with commendable gains in flame resistance, thermal stability, and mechanical robustness.