A filament modification approach for in situ ABS/OMMT nanocomposite development in extrusion-based 3D printing

In the present study, a filament modification approach is proposed for in situ nanocomposite development during the 3D printing process. The acrylonitrile butadiene styrene filament was modified by coating it with organically modified montmorillonite (OMMT)-based nanocomposite solution. On 3D printing with the modified filament, a fused network of nanoparticles and polymer develops on the perimeter of the deposited raster’s. This creates a unique mesostructure over the entire cross section of the 3D-printed part. Mechanical, thermal and dielectric properties were investigated to study the effect of filament alteration on 3D-printed parts. Microstructure and morphology of the nanocomposites were analyzed by XRD and SEM. The nanocomposite demonstrated 10.8% increment in Young’s modulus compared to pristine polymer due to the presence of stiffer OMMT nanoparticles. The ionic nature of OMMT contributed in enhancing the relative permittivity of the nanocomposite by 64%. Thermal stability of the nanocomposite was also enhanced, and the glass transition temperature was increased by 6.7oC. Experimental data were compared with the rule of mixture and Halpin–Tsai composite models. Further, the mesostructure of 3D-printed parts was considered to modify the Halpin–Tsai composite model for 3D-printed parts.