目的 研究纳米SiO2对可生物降解聚（3-羟基丁酸酯-co-4-羟基丁酸酯）（P34HB）包装膜结晶行为和力学性能的影响。方法 采用溶液浇铸法制备SiO2/P34HB纳米复合薄膜，利用红外光谱仪（FTIR）、扫描电镜（SEM）、正置热台显微镜（POM）、差示扫描量热仪（DSC）和万能力学试验机等研究纳米SiO2对P34HB结构、结晶性和力学性能等的影响。结果 纳米SiO2在P34HB中起到异相成核的作用，SiO2/P34HB复合膜的结晶速率和结晶度得到明显改善。相比P34HB包装膜，当纳米SiO2质量分数为2%时，SiO2/P34HB复合膜的弹性模量和拉伸强度分别提高了72.7%和60.9%。结论 获得了纳米SiO2改善可生物降解聚（3-羟基丁酸酯-co-4-羟基丁酸酯）包装膜结晶度和力学性能的最佳掺杂比例参数。

The work aims to research the effect of nano-SiO2 on the crystallization behavior and mechanical properties of biodegradable poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) packaging film. SiO2/P34HB nanocomposite films were prepared by solution casting method. The effects of nano-SiO2 on the structure, crystallinity and mechanical properties of P34HB were analyzed by FTIR, SEM, POM, DSC and mechanical universal testing machine. The results in-dicated that, nano-SiO2 played a heterogeneous nucleation role in P34HB. The crystallization rate and crystallinity of SiO2/P34HB composite films were significantly improved. Compared with P34HB packaging film, the elastic modulus and tensile strength of SiO2/P34HB composite film were increased respectively by 72.7% and 60.9%, when the mass fraction of nano-SiO2 was 2%. Finally, the optimum doping ratio parameters of nano-SiO2 for improving the crystallinity and mechanical properties of biodegradable poly(3-hydroxybutyrate-co-4-hydroxybutyrate) packaging film were obtained.