Simultaneous enhancements in damping and static dissipation capability of polyetherimide composites with organosilane surface modified graphene nanoplatelets

Polyetherimide (PEI) possesses excellent thermal resistance and advanced mechanical properties, for which it has been used as interior materials in various transportation structures. Multifunctional PEI nanocomposites, in particular, with high damping properties and satisfactory static dissipation capability, will be more significant for those applications. In this study, PEI/graphene nanoplatelet (GNP) nanocomposites were fabricated via solution processing. Effects of GNP loading and surface silanization of GNPs on damping capacity and static dissipation properties were studied. The addition of the GNPs effectively increased the storage modulus of PEI, especially storage modulus at higher temperature (200 °C). The silanization of GNPs, on one hand, improved the dispersion quality; on the other hand, provided strong interfacial bonding with PEI matrix, which benefited the stress transfer within the composites. The superior damping capacity enhancements for the resulting nanocomposites are: with the loading of 3.0 wt% silanized GNP, the storage modulus of PEI increased approximately 4 times and 200 times at 30 °C and 200 °C, respectively, and the damping factor is 3 times higher than PEI. In addition, with the addition of 3.0 wt% GNPs, both low electrical resistivity (∼106 Ω∗cm) and low dielectric constant (∼7) were realized, corresponding to excellent volume static dissipation capability, however, silanization resulting in good interfacial bonding did not cause invisible impact on the electrical and dielectric properties of the nanocomposites. The superior damping capacity and static dissipation property make them suitable for intra-structure materials for airplane and transportation.