Epoxy/GO nanocomposite adhesives reinforced with waste blends of PET/GTR: Evaluation of mechanical properties

In this work, the effects of the graphene oxide (GO) content and composition of waste blends of poly(ethylene terephthalate) (W-PET) and ground rubber tire (GRT) on the mechanical properties and lap-shear strength of epoxy adhesives have been discussed. Adhesives based on diglycidyl ether of bis-phenol A (DGEBA) were developed in which extrusion-blended waste blends of W-PET/GRT were incorporated at variable composition (80/20, 50/50, 20/80) together with malefic-anhydride grafted SEBS (SEBS-g-MAH) as a binding agent. Dumbbell-shaped samples and adhesively bonded steel-(epoxy/carbon fiber composite) joints were used to evaluate tension properties of adhesives. The results indicated that addition of 10 phr of SEBS-g-MAH compatibilized 20/80 w/w blend of W-PET/GTR with 0.3 phr GO to epoxy formulation resulted in an increase of modulus, tensile strength and toughness to 33.2, 247.9, and 551.2%, respectively. The stiffness of GO together with its proper adhesion to epoxy/(W-PET/GTR) was responsible for this behavior. The overall shear strength of the composite-metal samples adhered by developed epoxy formulation was increased by 101% compared to the neat epoxy matrix.