表面改性核桃壳对聚乳酸/核桃壳粉体复合材料性能的影响

采用硅烷偶联剂（ＫＨ５５０）对核桃壳粉体（ＷＳＰ）进行表面处理，运用熔融共混法制备聚乳酸（ＰＬＡ）／ＷＳＰ复合材料，研究了填料对ＰＬＡ基复合材料力学性能和热稳定性的影响。结果表明，硅烷偶联剂ＫＨ５５０添加量为ＷＳＰ质量的６％ （质量分数，下同）时，ＰＬＡ／ＷＳＰ 复合材料的拉伸、弯曲和冲击强度分别为４２．０９、６３．８９ ＭＰａ和１．６９ｋＪ／ｍ２，比未处理的复合材料分别提高了１９．１ ％、２０．６ ％和１９．８ ％；用硅烷偶联剂ＫＨ５５０表面处理改善了ＷＳＰ与ＰＬＡ间的界面相容性；ＷＳＰ填料添加量为５％和４０％时，复合材料的热降解活化能（犈ａ）比ＰＬＡ分别降低了１３．１、２９．８ｋＪ／ｍｏｌ，硅烷偶联剂ＫＨ５５０处理使犈ａ 降低幅度较小。

Effect of Surface Modification of Walnut Shell on Properties of Poly(lactic acid)/Walnut Shell Powder Composites

Walnut shell powder (WSP) was treated with a silicane coupling agent KH550 and was introduced into poly(lactic acid) (PLA) forming composites through melt blending. The effect of the surface treatment of WSP was studied. When the dosage of KH550 was 6wt% of the walnut shell, all the tensile, bending, and impact strengths of PLA/WSP composites were increased by 1.2 times, reached 42.09, 63.89 MPa, and 1.69 kJ/m2, respectively. SEM images indicated the compatibility between WSP and PLA was improved after surface modification. When the contents of WSP were 5 wt % and 40 wt %, the thermal degradation activation energies (Ea) of composites were 13.1 and 29.8 kJ/mol lower, respectively, than those of neat PLA. The surface treatment depressed the decrease in degradation activation energy.