Acid and alkali resistance of Acrylic polyurethane/R-SiO₂ nanocomposite coating

Abstract

The purpose of this study is to assess the influence of R-SiO₂ nanoparticles on acid and alkali resistance of acrylic polyurethane coating. The resistance of the coatings with and without 2.5 wt.% R-SiO₂ nanoparticles in 5 % HC1 solution and 5 % NaOH solution was investigated by monitoring the variations in functional groups of the coatings using IR spectroscopic analysis and the changes in their morphology using FE-SEM analysis, as well as their weight loss analysis. The results showed that R-SiO₂ nanoparticles at content of 2.5 wt.% significantly increased the acid and alkali resistance of acrylic polyurethane coating. After 20 days of immersion in 5 % HC1 solution and 5 % NaOH solution, the nanocomposite coating containing 2.5 % R-SiO₂ nanoparticles changed negligibly with a weight loss of about 1 % while the coating not containing R-SiO₂ nanoparticles was deformed seriously with a weight loss of about 3 %.