3D Printing of High Strength Thermally Stable Sustainable Lightweight Corrosion-Resistant Nanocomposite by Solvent Exchange Postprocessing

3D printing of cellulose acetate (CA)-based, sustainable, thermally stable nanocomposites is challenging due to their fast drying, nozzle clogging, and complex rheological behavior. In this study, we developed an extrusion-printable ink based on CA and cellulose nanocrystals (CNCs) using a trisolvent wet blending method, followed by a postprinting pore-inducing processing technique. The nanocomposites performed well in both tensile- and compression-based mechanical tests. Moreover, the nanocomposites demonstrated malleable deformation during compression testing without any premature fracture, unlike commercial commodity plastics. The thermal stability was assessed using thermogravimetric analysis, showing a ∼ 28 °C improvement in the onset degradation temperature after the addition of 5 wt % CNCs. Solvent tolerance tests against various solvents indicated excellent solvent resistance. The lightweight nanocomposites showed no deterioration, even after long-term exposure to water vapor. Finally, the anticorrosion behavior of the samples was evaluated as a coating material for metal (Al), demonstrating excellent protection against corrosive acid vapors. Thus, the application of 3D-printed CA material exhibits significant promise for implementation in the fields of lightweight, sustainable, and anticorrosive engineering materials.