Bio-based polymer composite with induction-heating capacity for Fused Filament Fabrication (FFF): Development, printability, and recyclability

The aim of this work is to develop a polymer composite that can be heated by magnetic induction and can be used in Fused Filament Fabrication (FFF) 3D printing processes. The composite is based on polylactic acid (PLA) containing different concentrations of magnetic nanoparticles (MNPs). For the study, different compounds were prepared by melt mixing in a laboratory extruder. The materials have been characterized in terms of heating capacity applying specific alternating magnetic fields. After this, various filaments for FFF have been produced and their morphology was assessed in terms of diameter consistency using callipers and micro-computed tomography (micro-CT). The distribution of MNPs within the thermoplastic matrix was evaluated using TEM and SEM microscopy and using micro-CT as a preliminary processability assessment in the FFF system. Then, the optimal concentration for the induction heating capacity was used to test filament printability and define optimum printing parameters, achieving an aesthetically pleasing printed sample. Finally, the recyclability of the magnetic composite was tested in terms of degradation temperature and mechanical properties (flexural strength), and its processability through FFF was also validated.