聚乳酸/麦秸秆纤维复合材料力学及吸水性能研究

以西北地区麦秸秆纤维（WSF）和聚乳酸（PLA）为原料，通过熔融共混的方式加工制备了PLA/WSF复合材料,研究了偶联剂γ—氨丙基三乙氧基硅烷（KH550）对PLA/WSF复合材料的力学性能、吸水性能及界面性能的影响。利用傅里叶变换红外光谱仪(FITR)对改性前后的WSF进行分析，采用扫描电子显微镜（SEM）研究了复合材料拉伸断面的形貌变化。结果表明，KH550与WSF中羟基的反应降低了WSF表面极性；随着WSF含量的增加，PLA/WSF复合材料的力学性能最终呈现下降的趋势；经KH550对WSF改性处理， PLA/WSF复合材料的力学性能得到提升，同时降低了复合材料的吸水性；KH550处理改善了WSF与PLA的界面相容性。

Study on Mechanical and Absorbent Properties of Poly(lactic acid)/Wheat Straw Fiber Composites

The poly(lactic acid) (PLA)/wheat straw fiber (WSF) composites were prepared by a melt-blending process. The effects of coupling agent, γ-aminopropyltriethoxysilane (KH550), on the mechanical properties, moisture absorption and interface performance of the composites were investigated. Moreover, the chemical structure of WSF was characterized by FTIR, and the morphology of the composites was detected by SEM. The results indicated that the reaction between the WSF and KH550 reduced the surface polarity of WSF, and the composites exhibited a decreasing trend in mechanical properties with an increase of WSF content. The mechanical properties of the composites were improved due to the modification of WSF with KH550, and their water absorption was also reduced after the WSF were modified by KH550. The SEM observation suggested that the interfacial compatibility of PLA with WSF was enhanced due to the surface treatment of WSF with KH550.