不同相容剂对FDM用PLA/木粉复合材料性能的影响

Effect of Different Compatibilizers on Properties of PLA/Wood Flour Composites for FDM

采用熔融沉积制造(FDM)工艺制备了聚乳酸(PLA)/木粉复合材料,研究了3种相容剂PLA-g-MAH(马来酸酐接枝聚乳酸)、POE-g-MAH(马来酸酐接枝乙烯-辛烯共聚物)和EPDM-g-MAH(马来酸酐接枝三元乙丙橡胶)对复合材料力学性能、加工流动性和热稳定性的影响,并使用扫描电子显微镜(SEM)观察了试样断面形貌。结果表明:与相容剂添加前相比,加入相容剂后复合材料的拉伸强度、冲击强度和弯曲模量均有所提升,且加工流动性得到改善,热稳定性提高,线材成型变得容易,打印试样的质量变好。其中以POE-g-MAH对复合材料的力学性能提高最大,复合材料的拉伸强度提高了32.11%,冲击强度提高了38.43%,弯曲模量提高了15.68%,对加工流变性能和热稳定性改善效果最好,打印试样质量好、精度高。SEM观察结果显示,相容剂的添加使复合材料裸露的木粉减少,木粉与PLA基体的两相界面变得模糊,其中POE-g-MAH的改性效果最佳。

The PLA/wood flour composites were prepared by FDM process,and the effects of three compatibilizers PLA-g-MAH,POE-g-MAH and EPDM-g-MAH on the mechanical properties,processing fluidity and thermal stability of the composites were studied,and the cross-section morphology was observed by scanning electron microscopy.The results show that the tensile strength,impact strength and bending modulus of the composites are improved,the processing rheological properties are improved,the thermal stability is better,the forming process of wires is easier and the quality of printed sample is better than that of the composites without compatibilizers.Among them,POE-g-MAH improves the mechanical properties of the composites most,and the tensile strength of the composites increases by 32.11%.The impact strength and bending modulus were increased by 38.43%and 15.68%,the processing rheological properties and thermal stability were improved best,and the quality and accuracy of printed sample was high.The SEM observation results showed that the compatibilizer reduced the exposed wood flour and blurred the two-phase interface between wood flour and PLA matrix.Among them,POEg-MAH has the best modification effect.