309. Comparative analysis of 3D-printed polylactic acid and acrylonitrile butadiene styrene: Experimental and Materials-Studio-based theoretical studies

Dibli B. Otieno, Geoffrey O. Bosire, John M. Onyari and Julius M. Mwabora; Journal of Polymer Research; (2022); DOI: 10.1007/s10965-022-03075-6

This article reports a combination of experimental and computational approaches that were used to study the properties of 3D-printed polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). Both experimental and ab initio structural computations were used to characterize the structural, electronic, optical and mechanical properties of printed packaging products. The 3D- printed PLA and ABS, which were obtained via lab-scale filament extrusion, exhibited tensile strengths of 39.07 and 16.12 MPa, respectively. Theoretical examination of both PLA and ABS was achieved by density functional theory (DFT) approach generated by the Cambridge Serial Total Package (CASTEP) and forcite module in the material studio (MS) software. Norm conserving module was used as the plane wave basis pseudopotential for ABS and PLA energy calculations, ensuring scattering properties of the pseudopotential were correctly reproduced. In all simulations, molecular structures were geometrically optimized using the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm. The exchange correlation functionals used in the determination of electronic properties of the polymers were generalized by gradient approximation under Perdew-Burke-Ernzehorf. The calculated band structure of 1.899 and 2.539 eV for PLA and ABS, respectively, and the computed density of states, all suggested poor conductivity for both materials. This phenomenon was supported by the low computed values of the work functions (Φ) 3.364 eV and 4.503 eV, which signified wide separation between the fermi and vacuum level hence reduced charge carriers. Overall, the good mechanical properties of PLA to ABS are in agreement with values obtained in other studies. In particular, PLA is a greener alternative in packaging and biomedical applications since it is derived from renewable resources and can be used in applications requiring biodegradability.