Investigation of manufacturability of in-situ crosslinked polylactic acid (PLA) and peroxide composite in additive manufacturing

Purpose: This study aims to enhance the interfacial strength between PLA layers by in-situ cross-linking of PLA/peroxide composites during 3D printing.Theory and Methods: A new composite material was developed by incorporating peroxide into the deposition of PLA filament using an FDM 3D printer. The mechanical properties of the printed parts were correlated with their structures, and SEM analysis was used to examine the morphological properties of the fracture surfaces. FTIR analysis was performed to detect chemical interactions between peroxide and PLA polymers.Results: FTIR analysis revealed a chemical interaction between PLA and peroxide, suggesting that peroxide modified the polymer chain structure, resulting in a new crosslinked composite material. In SEM analysis, new formations were observed on the surfaces of the fibers, confirming the improvement in interfacial bonding between the fibers and an increase in interlayer adhesion strength. The tensile strength of the printed PLA sample, which is widely used but has strength limitations, increased by approximately 27.5%.Conclusion: Experimental results demonstrate the production of composite material through in-situ cross -linking of PLA and peroxide polymers using a 3D printer. This cross-linking process improved interfacial strength between fibers and mechanical properties. While previous studies concentrated on reinforcing filaments before the printing process or enhancing the product through post-processing, this study introduces a novel and innovative concept of in-situ polymer cross-linking during sample fabrication.