Effect of the epoxy/amine stoichiometry on the properties of carbon nanotube/epoxy composites

Research paper by M. R. Gude, S. G. Prolongo, A. Ureña

Indexed on: 25 Nov '11Published on: 25 Nov '11Published in: Journal of Thermal Analysis and Calorimetry


The effect of different amine/epoxy ratios on different properties of an epoxy resin was evaluated. Also, different amounts of carbon nanotubes (CNT) were added in order to analyse which of these two factors is more relevant. Dynamic thermomechanical analysis and flexural tests were carried out. The results obtained for the epoxy resin are in agreement with that reported by several researchers. The glass transition temperature of the resin and composites is maximal for the amine/epoxy stoichiometric ratio, while the highest glassy storage and flexural modulus correspond to the epoxy-rich systems, showing that the most crosslinked network is not the stiffest one. The effect of changing the stoichiometry is more relevant than adding CNT to the epoxy resin used in this work. However, the addition of CNT causes more remarkable changes in the epoxy-rich resin, promoting an increase of the glass transition temperature and the elastic modulus.