PLA–Potato Thermoplastic Starch Filament as a Sustainable Alternative to the Conventional PLA Filament: Processing, Characterization, and FFF 3D Printing

The growing popularity of the fused filament fabrication (FFF) 3D printing technology in science, industry, and in-home use is associated with an increased demand for high-quality polymer filaments. This study presents an in-depth characterization and analysis of a self-made bio-based polylactide (PLA)/thermoplastic potato starch (TPS) filament dedicated for the FFF 3D printing technology. The obtained results were compared with the commercial PLA filament (FF). The series of conducted studies (i.e., Fourier-transform infrared spectroscopy, Raman spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis) revealed that both of the investigated filaments are stable under FFF 3D printing conditions. The mechanical test showed a correlation between the print orientation and raster angle on the strength features. The most favorable strengths values were recorded for the ZX_0° configuration, which were ∼18/22 MPa of tensile strength and ∼9/18 kJ m^–2 of Charpy impact strength for the PLA/TPS filament and FF, respectively. Also, it was observed that the developed bio-filament has a more hydrophilic surface and is more susceptible to hydrolytic degradation in the phosphate-buffered saline solution than the FF. The composting study (according to the EN ISO 20200 standard) revealed that the commercial PLA printouts remain intact, while the PLA/TPS samples showed a mass loss of 19%. Finally, the remarkable printability of PLA/TPS was successfully demonstrated by FFF 3D printing of personalized anatomical models and complex porous structures.