Thermogravimetric studies on Polyamide-6,6 modified by electron beam irradiation and by nanofillers

This paper reports the results of thermogravimetric studies on: (a) Polyamide-6,6 (abbreviated henceforth as PA66) specimens which were modified by electron beam radiation in air, (b) organic-inorganic hybrid nanocomposite films of PA66/silica prepared by the sol-gel technique and (c) unmodified multi-walled carbon nanotube (abbreviated henceforth as MWCNT) reinforced PA66 films. The activation energies were determined using the Kissinger and the Flynn-Wall-Ozawa methods, which do not require knowledge of the reaction mechanism. The results showed that PA66 specimens which received an irradiation dose of 200 kGy in air had a higher thermal stability than both the neat PA66 and PA66 specimens which received a radiation dose of 500 kGy in air. The PA66/silica hybrid nanocomposites up to a silica loading of 1.5 wt% also showed higher thermal stability over neat PA66 films. At MWCNT loadings of 0.5-1.0 wt% the composite films exhibited higher activation energies than the neat PA66 film but at higher MWCNT loading the activation energy was lower than that obtained for the neat PA66 film.