Effects of hot melt adhesives on the interfacial properties of overmolded hybrid structures of polyamide-6 on continuous carbon fiber/epoxy composites

Official URL: http://dx.doi.org/10.1016/j.compositesa.2020.106106

This study aims to increase effectivity of the overmolding approach for thermoset/thermoplastics hybrid composites. The samples were prepared by overmolding of polyamide-6 (PA6) onto fully cured continuous carbon fiber-reinforced epoxy composites with the aid of hot melt adhesives. Specifically, the influence of hot melt adhesive application at the interface between the thermoset and thermoplastic parts of hybrid composites was investigated. The experimental scheme highlights the effects of hot melt type and adhesive layer thickness (ALT) on the performance of these hybrid joints. Thermoplastic polyurethane (TPU) based hot melt adhesive performed better adhesion characteristics among others (copolyesters, polyolefin) according to findings from lap shear test and DMA analysis. The fracture surfaces observed with optical microscopy and SEM also confirmed the synergistic effect of these parameters.