Graphene Sheets as Novel Nanofillers in Epoxy Matrix for Improved Mechanical Properties

In this paper, we will be interested in bending tests on a polymer matrix reinforced with graphene nanofillers. The mechanical behaviour and the damage kinetics were determined. The samples were made using controlled dispersions of graphene nanoplatelets (GNP) in EPON 862 matrix. Various samples with different contents of GNP were made (0%, 0.5%, 1%, 2.5%, 5% and 10% by weight). Mechanical properties such as maximum stress, strain at break and Young's modulus were determined. After each test, the fracture surfaces were characterised using optical microscopy (OP) and scanning electron microscopy (SEM). Experimental results show that the fracture toughness of the GNP/epoxy-based nanocomposites decreases with an increasing percentage of nanofillers. The flexural strength of the samples with 10 wt% of graphene significantly decreased compared to neat epoxy. Based on Stress-Strain data and the analysis of the fracture surface, it seems that graphene nanoplatelets show an impact on the mechanical behaviour and the kinetics of the damage. The influences of the weight percentage of GNP on the EPON matrix properties and the performance of the nanocomposites are discussed. In addition, the evolution of bending performance and damage kinetics with graphene content was obtained and analysed.