3D Printing\nof High Strength Thermally Stable Sustainable\nLightweight Corrosion-Resistant Nanocomposite by Solvent Exchange\nPostprocessing

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