Estudo do desempenho térmico e mecânico de adesivo epóxi modificado com nanotubos de carbono e grafeno

Abstract

In the last years, repair solutions and metallic surface bonding using epoxy adhesives, has been increasingly developed and applied in the industry. Successful applications are recorded specially in the offshore industry, where the thermosetting polymer is used to repair pipelines which present thickness loss or holes through wall, vessels hull and other metallic structures in oil rigs. The material, combined with reinforcement fibers has been replacing traditional metallic welding where it is unfeasible. However, increasingly severe work conditions such as pressure and temperature, require the development of more resistant adhesives. This work objective is to analyze the mechanical and thermal properties of a commercial adhesive modified with Multi-Wall Carbon Nanotubes (MWCNT) and graphene, as well as evaluate adhesion and adherence of metallic bonded joints trough single-lap shear test. In this regard, it was produced epoxy/MWCNT and epoxy/graphene composites with 0,1 and 0,5% wt. concentration of MWCNT and graphene. Each different composition mechanically characterized by tensile test, three-point bending flexural test, uniaxial compression test accordingly to ASTM standards. Glass transition temperature (Tg) and other thermomechanical properties were evaluated using Dynamic Mechanical Analysis (DMA). Mechanical test results have shown enhancements of around 20% on Young modulus and 15% on break strength of epoxy/MWCNT composites. Improvements were also observed mainly for 0,5%wt nanofiller concentrations. The nanofiller s distribution and dispersion rate on the epoxy matrix were evaluated by Scanning Electronic Microscopy.