3D printer application properties of MFC-PLA composite filament fabricated with organosolv-derived MFC

Lignin-contained microfibrillated cellulose (LMFC) has recently received much attention with potential applications as reinforcement materials in polymer composites. This paper presented the applicability of organosolv-derived MFC reinforcement in a polylactic acid (PLA). Approximately 15.1% lignin containing pulp was prepared by organosolv pulping and then subjected to homogenization and solvent exchange processes to produce a powder form of LMFC with a 22.9 aspect ratio. The MFC-PLA filaments contained 1-10% wt% MFC were extruded and then FDM (fused deposition modeling) 3D-printed specimens were fabricated to evaluate mechanical and thermal properties of the composite. It was confirmed that high stress and low strain occurred as the MFC content increased in the MFC-PLA composite. Elastic modulus increased up to 57% and tensile strength increased up to 19% compared to neat PLA although extension and TEA (total energy absorption) were diminished. The differential scanning calorimetry (DSC) result showed that the MFC contents in the composite did not appear significantly, but the glass transition temperature (T_g) was decreased by about 10°C when MFC was added. The dynamic mechanical analysis (DMA) showed that the loss coefficient (tan D) was 1.7 at 50°C and lower at low temperatures compared to neat PLA, 3.3 at 60°C. Therefore, MFC-PLA composites are expected to have a more robust behavior at lower temperatures than neat PLA.