Effect of functionalized multi-walled carbon nanotubes on the curing behavior and thermal stability of epoxy resin

Multi-walled carbon nanotubes (MWNTs) were modified by triethlene-tetramine (TETA) in order to attain better dispersibility and stronger interfacial bonding between MWNTs and epoxy matrix. The influence of surface treated MWNTs on the cure behavior of the diglycidyl ether of bisphenol A (DGEBA)/2-ethyl-4-methyl imidazole (EMI-2,4) system was investigated with nonisothermal differential scanning calorimetry. It was found that the curing peak temperature (T-P) decreased with the addition of TETA-MWNTs. The curing apparent activation energy (E-a) was calculated through Kissinger method. In addition, the thermal behavior of TETA-MWNTs/DGEBA/EMI-2,4 was examined by thermogravimetric analysis, and the result showed the addition of TETA-MWNTs could increase the thermal decomposition onset temperature (T-B) and the degradation peak temperature (T-max) of the nanocomposites. Scanning electron microscopy images of fractured surface of MWNTs/epoxy indicated homogeneous dispersibility of TETA-MWNTs and strong interfacial adhesion between the TETA-MWNTs and the epoxy matrix in the nanocomposittes.