Improvement of barrier and mechanical properties of coating via aid of exfoliated nanoclay

DOI: 10.5176/2251-1857_M316.17

Authors: Priyanka G. Dhirde, Venkata G. R. Chada, B. P. Mallik and Nirmalya Moitra

Abstract: Protection of iron substrates from external chemical and abrasion forces is important for increasing its life time. Corrosion and scratch resistance properties of coating are thus significantly important to serve this purpose. Indeed, various commercially available products do exist to circumvent this problem via different mechanisms. However, specific lifetime of the component which usually degrades over time remains a standing problem. Being inert in nature the aluminosilicate platelets (thickness ~1 nm) of clays offers an attractive alternative for above mentioned additives. To maximize the efficiency of these aluminosilicate platelets in composite systems it is important to emancipate them from their natural periodic stacked structure, to form exfoliated composite. Thus, herein we will unveil approaches, in which, aluminosilicate platelets of montmorillonite (naturally occurring clay) has been exfoliated in various solvent based coating systems. The exfoliation was carried out in two step process, intercalation followed by exfoliation in film forming polymer matrix. Organic molecules with different chain length and structure have been intercalated and their performance in paint system have been evaluated. The intercalated MMT and the composite coatings were characterized by FT-IR, TGA, XRD, analysis. The performance of the resulting coatings for barrier (corrosion resistance) and mechanical property (Young’s modulus) were also evaluated applying different doses of nanoclay in coating formulation. The effect of solvent during the course of exfoliation and dispersion were also studied, which for the first time to the best of our knowledge shows huge advance while using in coating system. Obtained results were thoroughly evaluated, and show promising advancement for development advanced coating systems.
Keywords: Nanoclay, Montmorillonite, Ion Exchange, Organic Modification, Exfoliation, Barrier Properties