Effect of Thermal Expansion and Sonication on Mechanical Properties and Adhesive Toughness Measurement of Polymer/Graphene Composite

Graphite has attracted both academia and researchers due to its outstanding properties such as having strength 200 times stronger than steel, great efficiency of heat and electricity conduction, low cost and also facile fabrication. In this study, two facile approaches of producing nanosize graphite were performed; thermal expansion and sonication. Graphite that was produced are used as reinforcement in epoxy composite for adhesive applications. In order to determine the mechanical properties of the composite, tensile test was performed using Dumbbell shape of sample. The outcome of the test shows that 1 wt% of expanded graphite produce the highest value of Young Modulus which is 18 MPa. It was also found that adding more expanded graphite increased the ductility of composite by lowering epoxy brittleness. As for adhesive testing, double cantilever beam was used using Universal Testing Machine where the result shows that 1 wt% of expanded graphite demonstrates the highest value of adhesive toughness which is 9398 J/m2. The result of porosity-density indicates that porosity of composites will affect the mechanical properties. From the overall results, it is conclude that smaller weight percentage of expanded graphite produces better composite while for sonication process shows no difference at all. Thus demonstrates that time of dispersion does not give significant effect on the maximum load and stress of the composites.