FDM 3D Printing and Properties of WF/PBAT/PLA Composites

Fused deposition molding (FDM) is a commonly used 3D printing method, and polylactic acid (PLA) has become one of the most important raw materials for this technology due to its excellent warping resistance. However, its mechanical properties are insufficient. Polybutylene adipate terephthalate (PBAT) is characterized by high toughness and low rigidity, which can complement the performance of PLA. The biodegradable polymers produced by blending the two have thus been used to replace petroleum-based plastics in recent years, but the high cost of the blends has limited their wide applications. Introducing plant fibers into the blends can not only maintain biodegradability and improve the overall performance of the plastics but also reduce their costs greatly. In this study, the PBAT/PLA blends with a mass ratio of 70/30 were selected and mixed with wood flour (WF) to prepare ternary composites using a FDM 3D printing technique. The effects of WF dosage on the mechanical properties, thermal properties, surface wettability, and melt flowability of the composites were investigated. The results showed that the proper amount of WF could improve the tensile and flexural moduli of the composites, as well as the crystallinity and hydrophobicity of the printed specimens increased with the content of WF, while the melt flow rate decreased gradually. Compared to PBAT/PLA blends, WF/PBAT/PLA composites are less costly, and the composite containing 20 wt.% WF has the best comprehensive performance, showing great potential as raw material for FDM 3D printing.