Effect of halloysite nanotubes on corrosion protection properties of the self-curing epoxy resin coatings

Purpose The purpose of this paper is to study the effect of the nano tube fillers on the corrosion protection properties of the self-curing epoxy (SEP) coatings. Design/methodology/approach The self-curing epoxy (SEP) resin was synthesized via a reaction between diisopropoxy-bis ethylacetoacetato titanate and the epoxy resin. Halloysite nanotubes (HNTs) was surface modified by grafting (3-glycidoxypropyl) trimethoxysilane to obtain modified HNTs (mHNTs). The HNTs and mHNTs are used as nano tube fillers for the SEP coating. The thermal stability of the coatings was assessed via thermo-gravimetric analysis. The field-emission scanning electron microscopy (SEM) was conducted to analyze the surfaces and cross sections of the coatings. The anticorrosive efficiencies of the coatings were investigated by electrochemical measurements and a neutral salt spray test. Findings The results demonstrated that the additions of HNTs and mHNTs have little effect on the thermal degradation temperature of the SEP coating. However, the addition of the nanotubes reduced the corrosion resistance of the SEP coating. Originality/value The SEP coating itself showed excellent corrosion resistance without any reinforcement particles and is hence promising for application in the heavy-duty anticorrosion field of heat exchangers.