Simultaneously reinforcing and toughening poly(lactic acid) by incorporating reactive melt‐functionalized silica nanoparticles

Simultaneously reinforcing and toughening poly(lactic acid) (PLA) was carried out by adding a small amount of functionalized SiO 2 (f‐SiO 2 ) 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 SiO 2 .The structure characterizations revealed that large quantity of degraded PLA chains were grafted onto the surface of SiO 2 by transesterification, condensation, and esterification reactions during melt blending. Due to the improvement in dispersion and interfacial interaction in PLA matrix, the f‐SiO 2 exhibited an effective reinforcing and toughening effect for PLA, where the tensile strength, elongation at break, and impact toughness of PLA/f‐SiO 2 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‐SiO 2 , which also contributed to improving mechanical properties.