The Use of Agricultural Waste in the Modification of Poly(lactic acid)-Based Composites Intended for 3D Printing Applications. The Use of Toughened Blend Systems to Improve Mechanical Properties

The presented research focused on improving the mechanical properties of PLA-based composites reinforced with buckwheat husks (BH) particles. The research work was carried out in two stages. Firstly, the blend was prepared with the addition of polybutylene adipate terephthalate (PBAT) and thermoplastic starch (TPS), manufactured by injection molding technique, then the selected materials were prepared with the addition of BH filler, and the samples were prepared using the fused deposition modeling method (FDM). All samples were subjected to the assessment of material properties. Thermal and thermomechanical properties were evaluated using differential scanning calorimetry analysis (DSC) and dynamic thermal mechanical analysis (DMTA). Mechanical characteristic was evaluated using static tensile and flexural measurements and Charpy impact resistance tests. The research was supplemented with scanning electron microscopy analysis (SEM). It was found that the addition of PBAT and TPS greatly improves impact strength and elongation, especially with the addition of reactive compatibilizer. As expected, TPS, PBAT, and BH reduced the stiffness of the composites during DMTA testing. The presence of BH particles in the polymer matrix was observed to improve the crystallization behavior of PLA. The optimal content of BH filler in the composite was found to be 10%, which allowed to preserve good mechanical properties.