Development of Sustainable Cellulose Acetate‐Based Filaments for 3D Printing Through Plasticization and Natural Wax Incorporation

The integration of renewable biopolymers into value‐added engineering applications has become more critical. Cellulose acetate (CA) is a naturally derived polymer and widely used in the design‐oriented optical industry. However, its brittle structure and high melt viscosity limit processability in 3D printing technologies. This study aims to develop sustainable and 3D‐printable CA filaments using plasticizer and forest‐derived natural wax (PTEX) as a natural hydrophobic additive. In this study, filaments containing varying plasticizer contents (5, 10, and 15 wt%) and a constant PTEX content (5 wt%) were produced by single screw extrusion and subsequently printed using the Fused Deposition Modeling (FDM) technique. The results showed that adding plasticizer improved processability by lowering the glass transition temperature, and it was reduced from 158.38°C to 150.10°C with increasing plasticizer content. While the initial thermal degradation gradually reduced owing to plasticization, the main decomposition temperature of PTEX incorporated filament samples was approximately 18°C higher compared to neat CA. Meanwhile, adding PTEX improved the material's surface hydrophobicity, and the highest contact angle measured was 67.77°. Mechanical analyses revealed that increasing the amount of plasticizer improved the elastic modulus from 1168.12 to 1234.67 MPa. However, there was no statistically significant change in tensile strength. It was therefore concluded that the modified CA filaments developed offer a sustainable, functional alternative and printable material for additively manufactured industrial applications.