Effects of surfactant treatment on mechanical and microwave absorbing properties of graphene nanosheets/multiwalled carbon nanotubes/cyanate ester composites

Graphene nanosheets (GNSs) and multiwalled carbon nanotubes (MWCNTs) were treated with a nonionic surfactant polyvinylpyrrolidone (PVP), and its effects on dispersion state, surface chemistry, structure, and morphology of MWCNTs and GNSs, as well as on the microwave absorbing properties, mechanical properties of GNSs/MWCNTs/cyanate ester nanocomposites were analyzed respectively. Results show that surfactant plays an important role in dispersing the GNSs and MWCNTs in a solvent and polymer. The mechanical properties, such as impact fracture toughness and flexural strength all showed significant improvements after the treatment. The above observations are attributed to the unique amphiphile structures of PVP, which improved the interface characteristic between matrix and the fillers. Besides, PVP can effectively enhance interfacial interactions which gave rise to improved dispersion and wetting of GNSs and MWCNTs in polymer matrix. Unlike chemical functionalization techniques, however, the surfactant treatment exhibited little adverse effect on microwave absorption properties of the nanocomposite. POLYM. COMPOS., 39:110–118, 2018. © 2016 Society of Plastics Engineers