Development and characterization of fly ash enriched epoxy coatings for corrosion protection in deep sea water

Abstract

Fly ash (FA) has recently received increasing attention as inexpensive and readily abundant filler for development of epoxy-based anticorrosive coatings. In the present investigation a series of FA enriched epoxy coatings (FECs) has been developed and investigated for their anticorrosive behaviour under immersion in DSW (pH 8.2) over 48 h. The development of FECs was conducted through enrichment of FA ranging 0 to 80 phr (parts of FA per 100 g of epoxy) into epoxy matrix. The formation of FECs was ascertained through spectral, thermal, electrical and microscopic methods. Electrochemical impedance spectra in coherence with DC polarization measurements reveal enhanced corrosion protection efficiency (83 %) of FECs derived at 40 phr enrichment of FA. Enrichment of FA (phr) ranging 40 to 60 has rendered fair (0.01) to moderate (0.05) resistance (mm/year) to FECs against pitting corrosion in DSW. Whereas, FECs derived at 60 phr of FA has shown promising electrical behaviour, moderate heat resistance (TG onset 200 °C with 94.70 % weight residue) with enhanced limiting oxygen index (38.50 %). FECs developed in the present investigation may find their possible applications as anticorrosive coatings sustainable in DSW over 48 h.