Effect of Adding Natural Latex Mixed Adhesive on the Shear Strength of Aluminum - Cocofiber Composite Single Lap Join

Adhesive bonding is often found for engineering construction technology applications in industries such as aeronautics, automotive, electronics, and aerospace. Single lap joint type connections can be applied to dissimilar materials so that they can reduce the weight of construction. The objective of this study to determine the effects of adding natural latex adhesive to aluminum-cocofiber composites single lap joints. The research material uses two types of adherend, namely aluminum and cocofiber-reinforced composite with an Unsaturated Polyester matrix (UPRs) type Yukalac BQTN with a MEXPO catalyst. Adhesive bonding material uses epoxy resin and the addition of natural latex. The connection is carried out using a single lap joint adhesive bonding method between two different adherend materials. The adhesive material in the single lap joint is 0.2 mm thick using variations in the addition of natural latex adhesive to epoxy with variations of 5%NK: 95%EP, 15%NK: 85%EP, 25%NK: 75%EP, and 35%NK: 65%E.P. The adherend surface treatment was given by roughing the surface with sandpapering grid #150. The single lap joints shear test refers to ASTM D-1002. The test results indicated that the shear strength increases with the addition of 5% natural latex to the epoxy. The roughness treatment applied to the surface provides an irregular effect, thus increasing the bond between the adhesive and the adherend. In addition, it also improves the mechanical interlocking of the single lap joint. The failure modes after the shear stregth test that occur based on macro observations are cohesive, stock-break, thin layer cohesive, and fiber pull-out.