Investigating the weathering performance of epoxy silicone nanocomposite coatings containing various loadings of Glycidoxypropyltrimethoxysilane-modified Zinc oxide nanoparticles

This research presents the modification of ZnO nanoparticles by Glycidoxypropyltrimethoxysilane (GPTMS) to produce hybrid nanostructured additives to improve the weathering resistance of epoxy silicone coatings. The modified ZnO nanoparticles were incorporated into epoxy silicone coatings at different loading dosages. The coatings were then weathered in an accelerated weathering chamber and removed after specific intervals (0, 500, and 1000 h) for further characterization. The effect of different loadings of modified ZnO nanoparticles (0.1, 0.5, and 1 wt%) on the weathering resistance of epoxy silicone coatings was studied using SEM, AFM, FTIR, and contact angle measurement, UV–visible spectroscopy, optical microscope, gloss, Vickers hardness, and gonio-spectrophotometer. All results showed that the addition of modified nanoparticles effectively promoted (6 times improvement based on carbonyl index) the weathering resistance of the epoxy silicone coating. It was also concluded that the coatings filled at a low level (0.1 wt%) of GPTMS-modified ZnO provided much more superior weathering performance than those loaded with higher filler content (0.5 and 1 wt%). It was explained by the more crosslinked network formed and the fine distribution of modified filler within the matrix at low filler content. • ZnO nanoparticles were modified by Glycidoxypropyltrimethoxysilane (GPTMS). • The weathering stability of epoxy silicone containing modified ZnO was assessed. • The weathering performance was enhanced in the presence of functionalized ZnO. • The lower filler level (0.1 wt%) was more efficient than higher loadings (1 wt%). • Six times weathering stability improvement (based on carbonyl index) was achieved.