Self-assembled montmorillonite-carbon nanotube for epoxy composites with superior mechanical and thermal properties

A hybrid nanostructure consisting of montmorillonite−multi-walled carbon nanotube (Mt−MWCNT) was designed and assembled, and further used as reinforcing nanofillers for preparing epoxy-based composites. It was found that Mt could efficiently resist microcrack extension and hinder thermal transfer while MWCNTs anchored on the Mt nanosheets could facilitate the stress and heat transfers and provide mechanical interlocking with the epoxy matrix. Making use of the synergistic effect of Mt and MWCNT, considerable enhancement in thermal and mechanical properties was achieved in the composites. With addition of just 0.5 wt% Mt−MWCNT (Mt:MWCNTs = 10:1, w/w), the tensile strength and modulus of epoxy-based composites were improved by 42.0% and 20.3%, respectively, compared with pure epoxy. Furthermore, the storage modulus in the glassy region increased by 21.2%. Moreover, the glass-transition and onset decomposition temperatures were also significantly enhanced, implying the superior thermal stability of these composites.