Evaluation of mechanical and adhesive properties of 3D-printed ABS and PLA specimens using epoxy-based adhesives

This study investigates the influence of Grub Catalyst-modified epoxy adhesives on the tensile deformation behaviour of bonded fused filament fabrication (FFF) components. Additively manufactured ABS and PLA specimens with circular and triangular profiles were bonded using a commercial epoxy and a first-generation Grub catalyst-modified epoxy to evaluate improvements in joint ductility using displacement values. The statistical analysis revealed that the bonding agent was the dominant factor showing joint performance (F = 13.36, p = 0.022), whereas specimen profile and material exhibited comparatively minor effects within the investigated range. The catalyst-modified epoxy demonstrated a significantly higher mean displacement (∼6.2 mm) compared to the unmodified system (∼4.9 mm), resulted into increased energy absorption capacity. A scanning electron microscopy identified interlayer separation as the primary failure mechanism in ABS, whereas the PLA exhibited comparatively uniform interlayer bonding. It was analysed that Grub catalyst modification effectively enhances the ductility and displacement capacity of bonded FFF joints. The adhesive and cohesive fractures of the specimens have been shown using SEM images for detailed insights of the fracture mechanism. With the help of FTIR analysis, the chemical bond behaviour shown with respect to epoxy and grub catalyst of the specimen material.