Nanoindentation Study And Dielectric Analysis Of Pmma/graphene Nanocomposites

In this study,a series of PMMA/graphene nanocomposites by solutionmixing were prepared. The localized elastic properties, creep behavior anddielectric properties after Fe₃O₄particles doping were systematicallycharacterized by nanoindentation technique. Firstly, it was found that theaddition of graphene could improve elastic modulus, hardness and creepresistance of neat PMMA matrix, specially, with elastic modulus increasing byabout28%at3wt%filler content. Secondly, by combining of modulusmapping, Halpin-Tsai model and AFM contrast, it was concluded that themain reinforcing mechanism of graphene was a kind of simple reinforcement.Thirdly, the results of creep behavior analysis revealed that the key parametersof creep properties could be obtained by nanoindentation, such as stressexponent and relaxation time. And this method was superior to conventionalcreep testing. Finally, the dielectric behavior of nanocomposites can bechanged by Fe₃O₄particles doping. However, the load structure betweengraphene and Fe₃O₄cannot retain after mixing with polymer matrix. The fillercontent can influence its dispersion degree in polymer, which controls the dielectric properties. It’s believed that these experimental methods were quiteuseful for various polymer nanocomposites.