目的 添加适量的纳米纤维素改善聚乳酸的脆性，以适应产品的包装。方法 将聚乳酸(PLA)与纳米纤维素(CNFs)共混制备复合包装材料，测试该复合材料的力学性能、透光率、红外谱图，并用扫描电子显微镜(SEM)观察了复合包装材料的表面形貌。结果 纳米纤维素添加到聚乳酸中增加了其力学性能，当纳米纤维素质量分数为2%时，拉伸强度和冲击强度都达到最大；随着添加CNFS比例的增大，CNFs/PLA复合薄膜材料的透光率随之降低，雾度随之升高，但是该薄膜作为包装材料对商品的可视性影响不大。结论 纳米纤维素(CNFs)是具有一定长径比的纳米级线状材料，对材料的拉伸强度具有增强作用。

Moderate amount of cellulose nanofibers (CNFs) is added into poly (lactic acid) (PLA) to improve its brittleness for adapting to the packing of the products. PLA and CNFs were mixed together to prepare composite packaging material. The mechanical properties, light transmittance and fourier transfer infrared spectroscopy (FTIR) were tested, and the surface morphology of the composite packing materials was observed by SEM. The mechanical properties of the composite packaging materials increased after the CNFs was added into PLA. When the mass fraction of the CNFs was 2%, the tensile strength and the impact strength reached maximum. As the percentage of CNFs increased, light transmittance of CNFs/PLA composite film decreased, and the haze increased. But it had a little effect on the visibility as packaging material. In conclusion, CNFs is a nanoscale linear material with a certain length to diameter ratio. It has strong reinforcing and toughening effect.