Anticorrosive Coatings Prepared Using Epoxy–Silica Hybrid Nanocomposite Materials

Abstract

Organic−inorganic nanocomposite protective coatings were prepared by sol−gel method using 3glycidoxypropyl-trimethoxysilane (GPTMS), tetramethoxysilane (TMOS), or tetraethoxysilane (TEOS) as silane precursors to compare the effect of two types of alkoxysilane (i.e., methoxy or ethoxy functional group) on aluminum substrate properties. In addition, the TiO 2 and AlOOH nanoparticles were derived from tetra-n-butyl titanate and aluminum butoxide, respectively, and the protective effect of these nanoparticles on the GPTMS based coatings was investigated. The formation of AlOOH and TiO 2 nanoparticles and the uniform distribution of nanoparticles in the coatings were characterized by dynamic light scattering (DLS) and different microscopic techniques. Potentiodynamic scanning (PDS) and 2000 h salt-spray testing methods were used to investigate the corrosion resistance of these hybrid sol−gel coatings. The PDS results demonstrated that the corrosion protection of hybrid coatings depends mainly on the silane content, type of the silane precursor, and type of nanoparticles. The coating protective effect improved by increasing polarization resistance (Rp) for about one decade by replacing silane precursors from TEOS to TMOS. In addition, the incorporation of TiO 2 in comparison with AlOOH nanoparticles in the GPTMS based coatings showed improving effect on polarization resistance. However, the simultaneous incorporation of TiO 2 and AlOOH nanoparticles led to high protective coatings.

Functionalization of Silica with Triazine Hydrazide to Improve Corrosion Protection and Interfacial Adhesion Properties of Epoxy Coating and Steel Substrate

“…The defect area increased with lowering and increasing the SG wt.% to more than 3 wt.%. The same result occurred when silica was used as filler for the epoxy/polyamine hardener system [45]. The epoxy composites with AS photos (Figure 8c) showed no propagation of corrosion and blister formation with using 3 wt.% of AS after exposing of 750 h. However, the case of AS-embedded epoxy composites with 1 and 5 wt.% confirmed the initiation of corrosion on the scratched area on completion of 720 h exposure in seawater salt-spray.…”

Systematic investigation of mechanical properties and fracture toughness of epoxy networks: Role of the polyetheramine structural parameters

“…Epoxy resins are one of the most important classes of thermosetting materials that have attracted considerable attention due to their outstanding mechanical, electrical, chemical, and thermal properties. Epoxy resins are used in various engineering applications such as structural adhesives, coatings, composite materials, microelectronic encapsulants, and as skin binding in surgical incisions . Epoxies display a high degree of crosslinking as thermosetting materials, which provide them with useful properties.…”

Effects of nano- and micro-sized inorganic filers on the performance of epoxy hybrid nanocoatings

“…They showed that the inclusion of silica precursors in epoxy improves the properties of coating. 18-20 Gu et al studied the flame-retardant property of epoxy and silica nanoparticle-based composites in presence of conductive polymer, polyaniline. 20 Improved glass transition and enhanced mechanical properties of the epoxy composites were documented.…”