UV-cured epoxy/graphene nanocomposite films: preparation, structure and electric heating performance

UV-cured epoxy/graphene nanocomposite films with ca 100 mu m thickness were manufactured by a facile cationic photopolymerization of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate mixtures including graphene sheets of 0.3 - 10.0 wt%, which was initiated by triarylsulfonium hexafluoroantimonate salts. The microstructure and thermal and electrical properties of the UV-cured epoxy/graphene nanocomposite films were investigated as a function of the graphene content. X-ray diffraction patterns and TEM images confirm that graphene sheets are well dispersed in the UV-cured epoxy resin matrix even with a high graphene content of 10.0 wt%. The electrical resistance of the nanocomposite films decreased dramatically from ca 10(12) to ca 10(2) with increasing graphene content, especially at a percolation threshold of 2.0 - 3.0 wt%. Accordingly, the UV-cured nanocomposite films including 5.0 - 10.0 wt% graphene showed excellent electric heating performance in terms of temperature response as well as electric power efficiency at a given applied voltage. For a nanocomposite film with 10.0 wt% graphene, the maximum temperature of ca 138 degrees C was attained at an applied voltage of 15 V and a high electric power efficiency of ca 3.0 +/- 0.3 mW degrees C-1 was achieved. (c) 2014 Society of Chemical Industry