In‐situ generation of biodegradable poly(lactic acid)/poly(butylene succinate) nanofibrillar composites via a facile and cost‐effective strategy of pressure‐induced flow processing

Abstract

AbstractInspired by the fact that the in‐situ fibrillation structure can enhance the polymer's macroscopic mechanical performance, a facile and cost‐effective strategy based on the pressure‐induced flow (PIF) processing was developed to produce ultra‐strong and super‐tough biodegradable poly(lactic acid)/poly(butylene succinate) (PLA/PBS) blends. Under the action of external pressure field, the ductile and flexible PBS droplets deformed along the flow direction (FD) and shifted from spheroid to ellipsoid, eventually to nanofiber as the compression ratio (CR) increased. From the scanning electron microscopy (SEM) results, it was found that the PBS droplets did not in‐situ take shape into nanofibrils until the CR reached to 4, and the PBS nanofibrils served as the central shish to induce the PLA molecular chain to crystallize in the perpendicular direction, resulting in nanohybrid shish‐kebab superstructures. The Raman spectra and differential scanning calorimetry results confirmed the enhancement effect of the CR on the orientation degree, lamellar thickness, and crystallization properties. Benefiting from the abundant interlocked hybrid shish‐kebabs, the tensile strength, tensile modulus, and impact strength of the PIF processing PLA/PBS blend (CR = 4) reached the maximum value of 106.4 MPa, 2332.4 MPa, and 87.4 kJ/m2, respectively, which were 116.7%, 40.1%, and 20.8‐folds higher than those of the common PLA/PBS blend. Overall, it is believed that the proposed methodology put forward a facile and cost‐effective way to produce PLA‐based in‐situ fibrillation reinforced composites for engineering applications.