J. Pereira-Rojas, N. Barrios, D. Saloni
North Carolina State University,
United States
Keywords: FDM, bio-based, filaments, cellulose-materials
Summary:
The development of sustainable filaments for fused deposition modeling (FDM) is of growing interest as additive manufacturing advances toward bio-based and functional materials. Polylactic acid (PLA) is widely used in FDM due to its biodegradability and processability; however, its limited tunability in deformation and load-bearing behavior motivates the incorporation of renewable modifiers. Cellulose- based materials offer several advantages in this context, including renewability, low density, high aspect ratio, abundant surface hydroxyl groups, and the ability to tailor interfacial interactions and thermal behavior within polymer matrices. In this work, hydroxypropyl methylcellulose (HPMC) and cellulose nanofibers (CNFs) are explored as cellulose-derived additives in PLA to fabricate composite filaments and corresponding 3D-printed samples. PLA/HPMC and PLA/HPMC/CNF filaments are produced via melt extrusion under controlled processing conditions, with attention to minimizing moisture-related effects and thermal degradation. The extruded filaments are evaluated in terms of dimensional uniformity, handling, and printability to assess their suitability for FDM processing. Thermal characterization is carried out using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to examine thermal transitions, crystallization behavior, and thermal stability as a function of formulation and processing history. Tensile testing of filaments and printed specimens is performed to evaluate tensile strength, elongation at break, and Young’s modulus, enabling correlations between composition, thermal behavior, and tensile response. FDM printing trials are conducted to demonstrate the processability of the developed filaments using conventional printing equipment and to generate specimens for subsequent characterization. Overall, this ongoing study provides a systematic framework for evaluating the thermal behavior and tensile response of PLA-based filaments containing cellulose derivatives and nanofibers, highlighting the potential of cellulose incorporation to enhance sustainability, tunability, and functionality in materials for additive manufacturing.