Influence of silane coupling agents on the interfacial structure and properties of modified polypropylene/aluminum alloy composites prepared by hot-press molding

Polymer-metal hybrids were prepared by using the ultrasonic-assisted hot-press molding process. The surface of the aluminum alloy is anodized to produce nano-pores with a pore size distribution of 60 to 210 nm. The surface of the anodized aluminum alloy is soaked with a silane coupling agent solution to alter its surface polarity. In addition, PP-g-MAH was used to alter the polarity of polypropylene. The structure and properties of the composites were investigated by tensile shear tests, the microstructure of the bonding interface, and elemental analysis. The results show that adding silane coupling agents can create a chemical connection based on the mechanical interlocking structure of the composite bonding interface, leading to an increase in tensile shear strength. When the aluminum alloy surface was treated with a silane coupling agent with a volume fraction of 4%, the tensile shear strength reached 21.02 MPa, increasing by 20.32% compared to the specimen without the silane coupling agent treatment.