偶联剂对PLA/PBAT/WF复合材料3D打印性能的影响

以聚乳酸（PLA）和聚己二酸/对苯二甲酸丁二酯（PBAT）为基体，杨木粉（WF）为填充增强材料，使用混炼机熔融共混制备PLA/PBAT/WF复合材料，采用熔融沉积成型（FDM）技术制备标准实验试样，通过扫描电子显微镜、红外光谱分析、旋转流变测试以及力学试验等方法，研究不同含量的硅烷偶联剂KH550对PLA/PBAT共混物以及PLA/PBAT/WF的相容性、流变性及力学性能的影响。结果表明，在偶联剂用量为3 %（质量分数，下同）时，拉伸强度提高了136 %；偶联剂KH550与 PLA和PBAT共价键偶联生成接枝聚合物，二者相容性得到提高；同时偶联剂与WF表面羟基发生缩聚反应有效的改善了其与PLA/PBAT的基体相容性，PLA/PBAT/WF复合材料的FDM的制件力学性能得到较大提升；复合材料的黏度随偶联剂含量的增加呈下降的趋势，含量为3 %时线材的综合打印性能及制品质量最佳。

Effect of Coupling Agent on 3D Printing Performance of PLA/PBAT/Poplar Powder Composites

PLA/PBAT/poplar powder （WF） composites were prepared by melt blending using poly（lactic acid） （PLA） and poly（butylene adipate-co-terephthalate） （PBAT） as matrices and WF as a filler. The standard test specimens were then prepared by a fused?deposition?modeling （FDM） technology. The effect of silane coupling agent （KH550） on the morphology， and rheological and mechanical properties of the composites was investigated with scanning electron microscopy observation， Fourier?transform infrared spectroscopy， rotational rheometer and mechanical test machine. The results indicated that the composites achieve an increase in tensile strength by 136 % at the coupling agent content of 3 wt%. The silane coupling agent could be covalently coupled with PLA and PBAT to form a grafted copolymer， and therefore the compatibility between two phases was improved. Meanwhile， the polycondensation reaction between the silane coupling agent and the hydroxyl group on the surface of WF could also effectively improve its compatibility with the PLA/PBAT matrix. As a result， the mechanical properties of the composites were greatly improved. The viscosity of the composites decreased with an increase of coupling agent content. When the content is 3 %， the wire achieved the optimum comprehensive printing performance at the coupling agent content of 3 wt%， resulting in an optimum quality for the printed products.