Enhancing mechanical properties of epoxy/polyaniline coating with addition of ZnO nanoparticles: Nanoindentation characterization

Epoxy/Polyaniline (PANI) coating from our previous work was modified with ZnO nanoparticles at 0.5 and 1.0 wt%, while the percentage of PANI was kept constant (0.78 wt%). ZnO nanoparticles were disseminated in epoxy/PANI mixture using mechanical stirring and sonication with acetone as a facilitator for mixing. The effects of ZnO on mechanical and thermal properties of Epoxy/PANI were studied. Mechanical characterizations of the samples were carried out using conventional techniques (i.e. pendulum hardness, scratch and impact resistance) and nanoindentation. Whereas, thermal characterization were performed using DSC and TGA to study the effect of ZnO nanoparticles on the Tg and thermal stability of the coatings. The mechanical analysis results showed that nano hardness (from nanoindentation) and scratch resistance (scratch test) of the modified coating increased by maximum 15% compared to unmodified coatings. On the other hand, the impact resistance and elastic modulus (from nanoindentation) were decreased. The thermal analysis results showed that the addition of ZnO nanoparticles to Epoxy/PANI matrix decreased the glass transition temperature (Tg) and thermal stability of the matrix.