Simultaneously reinforcing and toughening poly(lactic acid) (PLA) was carried out by adding a small amount of functionalized SiO₂ (f‐SiO₂) with grafting degraded PLA chains in this work. Typically, the high shear force and high temperature condition of melt blending were employed to accelerate the degradation of PLA and graft the degraded PLA chains onto SiO₂.The structure characterizations revealed that large quantity of degraded PLA chains were grafted onto the surface of SiO₂ by transesterification, condensation, and esterification reactions during melt blending. Due to the improvement in dispersion and interfacial interaction in PLA matrix, the f‐SiO₂ exhibited an effective reinforcing and toughening effect for PLA, where the tensile strength, elongation at break, and impact toughness of PLA/f‐SiO₂ nanocomposite increased by 14.9, 47.8, and 30.3% compared to neat PLA. Besides, the degree of crystallinity of PLA was significantly improved by the added f‐SiO₂, which also contributed to improving mechanical properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48834.

中文翻译：

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通过掺入反应性熔融功能化二氧化硅纳米粒子，同时增强和增韧聚乳酸

在这项工作中，通过添加少量官能化的SiO ₂（f-SiO ₂）与接枝降解的PLA链，同时进行了增强和增韧聚乳酸（PLA）。通常，采用高剪切力和高温条件下的熔融共混来加速PLA的降解，并将降解的PLA链接枝到SiO _2上。结构表征表明，大量降解的PLA链被接枝到SiO ₂的表面上。通过熔融共混过程中的酯交换反应，缩合反应和酯化反应进行。由于改善了PLA基质中的分散性和界面相互作用，f‐SiO ₂对PLA表现出有效的增强和增韧效果，与纯PLA相比，PLA / f-SiO ₂纳米复合材料的拉伸强度，断裂伸长率和冲击韧性提高了14.9％，47.8和30.3％。此外，通过添加f-SiO _2可以显着提高PLA的结晶度，这也有助于改善机械性能。分级为4 +©2019 Wiley Periodicals，Inc.J.Appl。Polym。科学 2020，137，48834。