(364g) Epoxy Nanocomposites Reinforced with Soft and Hard Nanoparticles

Epoxy resin nanocomposites reinforced with both soft (polyaniline (PANI)) and hard (barium titanate (BaTiO₃)) nanoparticles are studied and compared with each other. For epoxy with PANI nanocomposites, both nanoshpere and nanofiber are applied to explore the morphology effect; and for epoxy nanocomposites with BaTiO₃ nanoparticles, the nanoparticle size (500 and 100 nm) effect on the nanocomposites is also studied. In addition, in order to improve the interfacial interaction between inorganic BaTiO₃ nanoparticle and organic epoxy resin, BaTiO₃ nanoparticles coated with PANI layer is synthesized, the amino group of PANI can react with epoxy monomer and improve the dispersion of the BaTiO₃ nanoparticle in epoxy resin. For all the series of samples, mechanical properties, rheological property, thermal stability, electrical conductivity and dielectric property are systematically studied. The Rheology test is based on liquid sample and reduced viscosity is observed in both PANI and BaTiO₃ samples at lower loading, and at higher loading, the viscosity increases with the loading increase. PANI as the soft nanofillers can increase the conductivity of matrix, and at same loading, epoxy with PANI nanofibers has lower volume resistance than epoxy with nanospheres, which is resulting from the contact resistance and a 3-d variable range hopping (VRH) electron transport mechanism. The dielectric property test indicates nanocomposites with both soft and hard nanofiller have higher real permittivity and less dielectric loss than those of pure epoxy. And the highest real permittivity is observed in epoxy with BaTiO₃ nanoparticle coated with PANI layer sample, the high real permittivity may be associated with the ferroelectric nature of BaTiO₃ and the space charge at the interface between BaTiO₃ and PANI.