Effect of zirconia nanoparticles modified by silane coupling agent on some properties of epoxy coating

Abstract

Effect of zirconia nanoparticles (zirconia NPs/ZrO₂ NPs) modified by 3 wt.% (glycidyloxypropyl) triethoxysilane - GPTES (m-ZrO₂ NPs) on some properties of epoxy coating such as mechanical properties, thermal stability and anti-corrosion performance was investigated. The obtained results indicated that the addition of zirconia nanoparticles to epoxy coating could enhance the properties of this coating. The addition of 2 wt.% of pure ZrO₂ NPs (u-ZrO₂ NPs) to the epoxy matrix could increase the mechanical properties (hardness and adhesion to the steel substrate) by approximately 10 %, the onset temperature of thermal degradation of the epoxy/u-ZrO₂ NPs coating was 4.4 oC higher, and the anti-corrosion performance of epoxy coating was improved in comparison with the neat epoxy coating. Organically modified ZrO₂ NPs had higher improvement for epoxy coating’s properties than pure ZrO₂ NPs. The epoxy coating filled with m-ZrO₂ NPs had 19.7 % higher in relative hardness, 88.73 % more in adhesion to steel substrate, 25.6 oC higher in the onset temperature of thermal degradation, and higher anti-corrosion performance in comparison with the epoxy coating filled with 2 wt.% of pure zirconia nanoparticles. The cross-section FESEM images of the epoxy/m-ZrO₂ NPs coating showed that m-ZrO₂ NPs could regularly disperse in epoxy polymer matrix while unmodified zirconia nanoparticles (u-ZrO₂ NPs) were agglomerated to big cluster in the epoxy coating. This was the reason for the high performance of the epoxy coating filled with zirconia NPs modified by GPTES.