Epoxy nanocomposites: Analysis and kinetics of cure

AbstractThe effect of organo‐nanoclay (Nanomer I30E) on the cure mechanism and kinetics of epoxy nanocomposites based on Epon 828 and Epicure 3046 was studied by means of dynamic differential scanning calorimetry (DSC) at four heating rates (2.5, 5, 10, and 20°C·min−1) and by Fourier transform infrared (FT‐IR) spectroscopy. The DSC cure data for epoxy‐amine mixtures with and without nanoclay was modeled by means of different approaches; the Kissinger and isoconversional models were used to calculate the kinetics parameters while the Avrami model was utilized to compare the cure behavior of the two systems. The Nanomer I30E was shown to initiate rapid homopolymerization of the Epon 828 resin at temperatures above 180°C. For the epoxy‐amine mixtures, the presence of nanoclay had little effect on the cure kinetics in the early stages (i.e., at lower temperatures), and the apparent activation energy was around 60 kJ·mol−1. However, in the later stages, the apparent activation energy increased significantly in the absence of nanoclay, but did not do so when it was present. The presence of nanoclay also lowered the final glass transition temperature by about 4°C. Polym. Eng. Sci. 44:1132–1141, 2004. © 2004 Society of Plastics Engineers.