Epoxy/ionic liquid-like MWCNTs composites with improved processability and mechanical properties

Abstract

Carbon nanotubes (CNTs) reinforced polymer composites are highly desirable as ideal candidates of light-weighting structural and multifunctional materials due to their potential to combine the superior performance of individual constituents. However, the development of polymer/CNTs composites remains limited due to the long-standing issues on manufacturing challenge to achieve uniform dispersion of nanoscale filler, and the rapid ascent of the viscosity induced by the high-aspect-ratio CNTs. In this work, ionic liquid-like MWCNTs (MWCNTs-iL), which have high densities of covalently grafted organic moieties and keep liquid state at room temperature, are introduced into epoxy matrix. Since the compatibility of MWCNTs-iL and the epoxy matrix is efficiently improved, the epoxy/MWCNTs-iL composites exhibit homogeneous dispersion and 69.1% shear viscosity reduction compared to traditional epoxy/MWCNTs composites with 8 wt% loading of MWCNTs. MWCNTs-iL with stiff nanotube core and soft polyether shell play the simultaneous reinforcing and toughening roles in epoxy-based composites. Additionally, the influences of the MWCNTs defect concentration on the electrical and thermal conductive properties of epoxy-based composites as a function of filler contents are also investigated.