Constructing In situ microfibrillar PA6/PLA composites with high strength and high toughness by a strong shear flow field

In situ microfibrillar PA6/PLA composites (MFCs) with high strength and toughness were produced via a multistage stretching extrusion system. The PA6 microfibrils induced the growth of PLA crystals perpendicular to the PA6 microfibrils and significantly enhanced the mechanical properties of the MFCs. Notably, the PLA-9 sample with 9 wt% PA6 microfibrils achieved excellent tensile strength and elongation at break (79.1 MPa and 77.8 %, respectively), which were 1.3 and 13.4 times than those of neat PLA. During the tensile process, the PA6 microfibrils underwent plastic deformation accompanied by the detachment and fragmentation of the PLA lamellae. The formation of shish-kebab structure significantly improved the tensile strength and elongation at break of in situ microfibrillar PA6/PLA composites. [Display omitted] •The MFCs achieved significantly improve in tensile strength and elongation at break.•The formed PLA crystal was the classic shish-kebab structure.•The tensile stress can be effectively transferred from the matrix to the PA6 microfibrils.•The PLA lamellae underwent detachment and fragmentation during the tensile process.