Characterization of steel lined with multilayers of micro/nano-polymeric composites

A more cost-effective method to prevent steel structures from degradation is coating. This study investigated a comparison between different configurations of three multilayers polymeric coating on both sides of steel. Epoxy filled with 1 wt%, 2wt%, and 3wt% micron or nano-sized alumina (Al 2 O 3 ) particles represents the coating layers to steel on both sides. Mechanical and barrier resistance properties were conducted on the micro/nanocomposite coated specimens and compared with pure epoxy coated specimens. Barrier resistance was performed by immersing the lined steel specimens in salt solution and in citric acid medium. Adding alumina (Al 2 O 3 ) particles in micron and nano size to epoxy coatings improves the barrier resistance, the tensile and hardness under dry and wet conditions as compared to pure epoxy coating. The maximum improvement of the tensile strength and barrier resistance was attained with the addition of 1wt% Al 2 O 3 nanoparticles. Further increases in Al 2 O 3 micro/nanoparticles cause deterioration in tensile strength and barrier resistance. Good properties were observed with stepwise graded micro/nanocomposite coatings. However, the maximum improvement of hardness under dry and wet conditions improved with the further addition of 3wt% Al 2 O 3 nanoparticles to epoxy coatings.