Simultaneous Compatibilization and Toughening of Renewable PLA/PA11 Blend via Core-Shell Biobased Nanosilica-Filled Elastomer

Abstract Poly(lactic acid) (PLA) composites are attractive candidates for sustainable applications. However, achieving an optimal balance between toughness and heat resistance without sacrificing biobased content remains a persistent challenge. Herein, we develop PLA composites exhibiting concurrently high stiffness, toughness, and heat resistance by incorporating renewable polyamide11 (PA11) and a biobased amino-functionalized nanosilica/epoxy elastomer hybrid (Ex). The influence of filler loading on mechanical performance, rheological behavior, and phase morphology of the PLA/PA11 blends is systematically investigated. The optimized formulation, 55-5E10 (comprising 5 wt % modified elastomer E10 with 10 wt % SiO2), achieves a tensile strength of 61.7 MPa, a notched impact strength of 49.8 kJ/m2, and an elongation at break of 399%. These marked enhancements are attributed to the formation of a co-continuous phase architecture, improved interfacial compatibility, and the preferential localization of EMG and EMG@SiO2 particles within the PA11 domains, featuring a multi-core architecture. This work offers a novel pathway for engineering mechanically robust PLA/PA11 composites, broadening their potential as fossil-free alternatives for load-bearing applications.