Functionalization of carbon nanotubes for fabrication of CNT/epoxy nanocomposites

Abstract To improve the dispersion of carbon nanotubes (CNTs) in epoxy matrix composites, polystyrene sulfonate (PSS) and poly(4-aminostyrene) (PAS) were attached on the surface of CNTs by noncovalent functionalization. In the case of PAS, amino groups can also generate chemical bonding with the epoxide groups in the epoxy matrix. CNTs noncovalently functionalized with PSS and PAS were then fabricated to obtain CNT/Epoxy nanocomposites with enhanced mechanical properties. The incorporation of noncovalently functionalized CNTs into the modified bisphenol-A type epoxy matrix yielded Young's modulus of 3.89 GPa and tensile strength of 82.59 MPa with the addition of 1 wt.% PAS-CNTs. The noncovalent functionalization of CNTs was effective in improving the composite's mechanical properties due to their enhanced dispersion and strong affinity with the epoxy matrix.