目的 添加适量椰纤维（CF）改善聚乳酸（PLA）的力学性能，以适应产品的包装。方法 采用熔融共混法制备不同CF含量的CF/PLA 复合材料。通过力学性能测试、扫描电子显微镜观察和动态热力学性能测试，探讨添加不同含量的碱洗CF对复合材料力学性能的影响。结果 与纯PLA相比，复合材料的拉伸强度降低，冲击强度增大，储能模量增大，玻璃化转变温度降低。当碱洗CF质量分数为3%时，复合材料的冲击强度比纯PLA增加了24%。结论 添加CF有利于提高复合材料的力学性能，碱液浸泡更有利于改善CF和PLA基体的界面相容性。

The work aims to improve the mechanical property of polylactic acid (PLA) by adding an appropriate amount of coir fiber (CF), so as to adapt to the product packaging. Coir fibers were pretreated by alkali treatment, and then mixed with PLA to make coir fiber-reinforced PLA composites (CF/PLA) with melt-blending method. The tensile strength, impact strength, micro-morphology of surface and the dynamic thermomechanical property of composites at different CF content were investigated. Compared to pure PLA, the impact strength and the storage modulus of composites increased, while the tensile strength and glass transition temperature decreased. At alkali-treated coir fiber content of 3%, the value of impact strength of composites was increased by about 24% as compared to that of neat PLA. Thus CF/PLA blends reinforced with the treated fibers exhibited superior mechanical properties than neat PLA.