Additive manufacturing of a super toughened biodegradable polymer blend: Structure-property-processing correlation and 3D printed prosthetic part development

Super toughened polymer materials have garnered significant attention from the scientific and industrial communities due to their vast application potential. However, a notable gap exists in the exploration of additive manufacturing (AM) of biodegradable polymer blends with enhanced impact resistance. This research addresses this gap by investigating the AM of a resilient green blend comprising PLA, BioPBS, and PBAT to achieve an enhanced impact resistance. To characterize the blend, rheological analysis, differential scanning calorimetry, thermomechanical analysis, and mechanical testing were performed. The printing parameters varied were the nozzle temperature, infill density, top and bottom solid layer raster angles, and infill pattern. This study is the first attempt to investigate the impact of the raster angle of top and bottom solid layers, which is important for determining the structural integrity of printed objects. The study revealed that a nozzle temperature of 180 °C, a rectilinear infill pattern, 100% infill density, and solid layers raster angle of 0° resulted in high mechanical properties with a notched Izod impact strength of 489.75 ± 16.6 J/m. Additionally, the study compared the mechanical properties of 3D printed and injection-molded samples. The 3D printed samples demonstrated comparable tensile strength to injection-molded samples, with only a 2% difference, and exhibited higher tensile and flexural moduli, showcasing 8 and 10% increases, respectively. However, there was a 10% decrease in impact strength compared to that of the injection-molded counterparts. These findings indicate that the 3D printed blend offers mechanical properties comparable to injection molding, making it a promising alternative for biomedical applications. A 3D printed leg prosthesis prototype has been developed using the formulated blend at optimized printing conditions.