Surface metamorphosis in FDM-Printed PLA and PLA+WF: A microstructural and analytical chemistry approach

The integration of bio-based materials in additive manufacturing is a key strategy in aligning with the Sustainable Development Goals (SDGs 9, 11, 12, and 13), particularly for fostering sustainable urban infrastructure and reducing environmental impact. This study investigates the surface metamorphosis of fused deposition modeling (FDM)-printed polylactic acid (PLA) and PLA reinforced with wood fibers (PLA+WF), using a combined microstructural and analytical chemistry approach to enhance surface functionality. Employing scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and surface profilometry, we characterized the morphological and chemical transformations induced by post-processing treatments such as controlled thermal annealing and solvent vapor exposure. The PLA+WF composites exhibited a 38% reduction in surface roughness (Ra) and a 22% increase in hydrophilicity compared to untreated PLA, facilitating better coating adhesion and reduced microbial accumulation. FTIR analysis confirmed the retention of key ester and cellulose functional groups post-treatment, ensuring material integrity. Moreover, thermal post-treatment improved the crystallinity index by 18% in PLA and 27% in PLA+WF, suggesting enhanced mechanical stability. These findings present a viable pathway for producing high-performance, bio-based components with improved surface characteristics, directly contributing to the development of sustainable, low-impact technologies in urban applications.