A fused deposition modeling method was used in this research to investigate the possibility of improving the mechanical properties of poly(lactic acid) by changing the thermal conditions of the printing process. Sample models were prepared while varying a wide range of printing parameters, including bed temperature, melt temperature, and raster angle. Certain samples were also thermally treated by annealing. The prepared materials were subjected to a detailed thermomechanical analysis (differential scanning calorimetry, dynamic mechanical analysis, heat deflection temperature (HDT)), which allowed the formulation of several conclusions. For all prepared samples, the key changes in mechanical properties are related to the content of the poly(lactic acid) crystalline phase, which led to superior properties in annealed samples. The results also indicate the highly beneficial effect of increased bed temperature, where the best results were obtained for the samples printed at 105 °C. Compared to the reference samples printed at a bed temperature of 60 °C, these samples showed the impact strength increased by 80% (from 35 to 63 J/m), HDT increased by 20 °C (from 55 to 75 °C), and also a significant increase in strength and modulus. Scanning electron microscopy observations confirmed the increased level of diffusion between the individual layers of the printed filament.

The research presented in this article discusses the subject of poly­(lactic acid) (PLA) modification via reactive mixing with the poly­(butylene adipate-co-terephthalate) (PBAT) copolymer for 3D printing applications. Filaments suitable for fused deposition modeling were prepared from blends of PLA containing 10, 20, and 30% by weight of PBAT. Mechanical testing clearly indicated that the blending with PBAT effectively increases the impact strength of PLA, from an initial value of approximately 30 J/m to more than 700 J/m for the optimized PLA/PBAT (30%) chain extender-modified blend. The addition of the multifunctional chain extender (ESA) also has a positive effect on the rheological profile of the PLA/PBAT materials, which facilitates both the production process of the extruded filament and the maintenance of a stable width of the printed material path. Despite the use of a significant PBAT content, the analysis of thermomechanical properties did not show any significant deterioration in the thermal resistance of the materials, while a detailed differential scanning calorimetry analysis indicates a small tendency to nucleate the PLA structure by PBAT inclusions. The structural analysis of scanning electron microscopy clearly indicates a change in the mechanism of deformation from a brittle fracture for pure PLA to a more favorable shear yielding for PBAT-rich blends. The comparison of the properties of printed and injected PLA/PBAT blends indicates the possibility of obtaining similar or in some respects better mechanical properties, especially for ESA-modified samples.

Excellent sub-micrometric dispersions in ternary blends were reached by blending a semi-polar PLA at low viscosity in PA6/PP formulations.

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The physical properties of biocarbon vary widely with the biomass used, and the temperature and duration of pyrolysis. This study identifies the effects of feedstock characteristics and pyrolysis conditions on the production of biocarbon and the corresponding properties for industrial applications. For coffee chaff and soy hulls, ash content and carbon content increased with pyrolysis temperature and duration. Ash content increased thermal conductivity and specific heat, and decreased electrical conductivity. Change in surface area with pyrolysis conditions was dependent on type of feedstock. Increased surface area corresponded with increased thermal and electrical conductivity. Increased carbon content corresponded with increased graphitization and thermal stability and decreased surface functionality. Properties of soy hull biocarbons were found to be similar to the properties of other biocarbons with industrial applications such as incorporation into polymer composites.