Multifunctional polymer composites reinforced by carbon nanotubes–Alumina hybrids with urchin-like structure

Abstract Polymer composites with enhanced mechanical and functional properties are highly desired to develop light-weight function-integrated structures and devices. In this study, one kind of urchin-like hybrids was synthesized by in-situ growing CNTs on alumina microspheres (μAl 2 O 3 ), and their reinforcing effects to epoxy were investigated in detail. It was found that as compared to pure epoxy the CNTs-μAl 2 O 3 hybrids/epoxy composites possess highly improved electrical, dielectric, thermal and mechanical properties, achieving an enhancement as high as 5 orders of magnitude in the AC conductivity, 92% and 56% in the thermal diffusivity and thermal conductivity, respectively, and 26% in the Young’s modulus, when CNT mass fraction used was 2%. Detailed analyses and various microstructural characterizations were also conducted in order to understand the multiscale reinforcement effects. The significant enhancements observed are mainly due to the urchin-like structure and improved CNT dispersion in the epoxy matrix.