Studies on epoxy nanocomposite coatings for corrosion protection

Abstract

Metallic corrosion is a multi-million dollar problem. Polymer based newlinesurface coatings is the most straight forward approach to protect metals newlinefrom corrosion. Epoxy itself forms a very good barrier in protecting metallic newlinesurfaces. Improving the corrosion resistance of epoxy coating further by newlineusing suitable modifiers is the topic of this thesis. A comprehensive newlineliterature survey leading to objectives and scope of the present work is given newlinein chapter 1. newlineThe specifications of the materials used, experimental methods newlineemployed for modifying the epoxy and techniques used for characterization newlineof the modified epoxy are presented in chapter 2. newlineThe nature and type of the base epoxy coating play a vital role in newlineprotecting the metal against corrosion. Basically two types of coatings were newlineprepared in this work by selecting a general purpose epoxy resin and curing newlineit with two types of crosslinkers, one of which gives a soft product and the newlineother a hard product. The kinetics of the curing reactions were analyzed newlineusing differential scanning calorimetry (DSC). The details of this study are newlinepresented in chapter 3. newlineModification of soft epoxy by carbon based conducting nanofillers newlineis the topic of chapter 4. Two types of conducting nanofillers, PANI coated newlinechitin (PANI chitin) and PANI coated silica (PANI silica) were prepared in newlinethe laboratory for this purpose. In order to evaluate their efficiency in newlinemodifying the corrosion resistance of epoxy, their performance was newlinecompared with those of two commercially available carbon based newlineconducting nanofillers, multiwalled carbon nanotube (MWCNT) and newlinegraphene. PANI coated chitin and PANI coated silica are found to besuperior to MWCNT and graphene in improving the corrosion resistance of newlineepoxy. This offers scope for detailed and extensive research in generating newlinelow cost carbon based conducting nanofillers as corrosion resistant newlinemodifiers by coating conducting polymers over inert fillers.