Sem Studies of Tensile Fractured Surfaces of Expanded Graphite/Acrylonitrile/Methyl Methacrylate Nanocomposites Prepared via in-Situ Polymerization

Expanded graphite/Acrylonitrile/methyl methacrylate nanocomposites of different weight contents (0 to 5 wt. %) of Expanded Graphite (EG) were prepared via polymerization and examined for their yield and failure behaviours under uniaxial stress state. The failure mechanism shows transitions from sheared to crazed states as the volume contents of EG were increased. SEM photomicrographs also confirmed the brittle to ductile microstructural transitions of the nano- composites. The toughness of the nanocomposite with 3 wt. % EG was optimum, and the process of crack growth which led to this high toughness could be seen. The decisive parameter which influenced the fracture data of EG/AN/MMA nano- composites was found to be volume fraction of EG and interfacial adhesion of AN/MMA matrix and EG particles.