Study on the interfacial bonding mechanism of nano-injection molding PPS/PA6@Al: A molecular dynamics simulation study

Nano-injection molding technology is widely used in producing lightweight and high-strength composites. In this study, seven polymer-metal interfacial models with inverted trapezoidal nano-slots were constructed using the polymers polypropylene sulfide (PPS), polyamide 6 (PA6), and the metal aluminum (Al), where the formula ratio of PPS/PA6 is different. Molecular dynamics simulation was used to analyze the PPS/PA6 motion behavior and interfacial bonding mechanism during the nano-injection molding process of the PPS/PA6 blend modification. The results indicated that the addition of strongly polarized PA6 to the inert material PPS could effectively enhance the interfacial bond strength of PPS/Al. Because the strong polar amide group in PA6 increased the force between the molecular chain and the metal surface, which led to more anchors forming between the interfaces, the number of anchors at the heterogeneous interfaces increased with the increase of PA6 content. In the interfacial damage simulations, adding PA6 enhanced the interfacial bonding energy, which required greater loading stresses to disengage the anchored molecular chains from the interface.Highlights Strongly polarized amide groups in PA6 enhance the forces. Addition of strongly polar PA6 gets higher interfacial energy and filling ratio. Failure modes: Y-shear and Z-tensile.