Characterization of the fracture behavior and viscoelastic properties of epoxy-polyamide coating reinforced with nanometer and micrometer sized ZnO particles

The mechanical and viscoelastic properties of an epoxy-polyamide coating containing nano and micro sized ZnO particles were studied. The nanocomposites were prepared at different loadings of the nano sized ZnO particles. The composites were also prepared using micro sized ZnO particles at different lambdas (lambda (lambda) = PVC/CPVC). The optical properties of each nanocomposite were studied by UV-vis technique. Dynamic mechanical thermal analysis (DMTA) and micro-Vickers were used to investigate the mechanical properties of the composites. The viscoelastic properties of the composites were studied by a tensile test. The fracture morphologies of the composites were studied by a scanning electron microscope (SEM). An increase in Tg together with a decrease in cross-linking density of the composites was obtained when the coating was reinforced with the micro sized ZnO particles. On the other hand, the Tg and cross-linking density of the composites were decreased using nano sized ZnO particles. It was also found that, the Young's modulus and the fracture energy of the coating were decreased using micro and nano sized ZnO particles. The greater toughness as well as fracture energy of the composite was obtained when it was reinforced with the nano sized ZnO particles. The curing behavior of the epoxy coating was affected in the presence of the micro and nano sized ZnO particles. (C) 2011 Elsevier B.V. All rights reserved.