Preparation And Corrosion Resistance Of Composite Waterborne Epoxy Resin Coating

The thesis carried out the research and development of low-cost,high-performance composite water-based epoxy resin coating.In this study,a water-based epoxy resin（3EE101W）was used as an example to improve the compatibility of the corrosion inhibitor material graphene oxide（GO）with water-based resin coatings through the modification of the coupling agent and the use of polymer polyvinyl alcohol（PVA）as the water-based the curing agent of the coating is used to study the corrosion resistance of the composite coating in two ways.The main research contents are as follows:（1）The coupling agent（[3-（2-aminoethyl）aminopropyl]trimethoxysilane）modified GO can effectively improve the dispersion and compatibility of GO with water,and reduce the contact angle from 45°to 20°.Under the premise of not destroying the structure and morphology of GO itself,the modification can effectively graft a large number of hydrophilic functional groups on the surface of GO,which can not only effectively broaden the interlayer spacing of GO,but also generate more reaction sites,which can make GO disperse better in water-based coatings and at the same time play a high barrier function.（2）The successfully prepared GO and modified graphene oxide（MGO）are combined with water-based epoxy resin to form a composite coating,and the dispersion and corrosion resistance of the two corrosion inhibitor materials in the coating are explored.The corrosion resistance of the composite coating and the single water-based epoxy resin coating is compared by means of correlation analysis and testing.The composite water-based coating material with 0.5 wt.%MGO content shows the best corrosion resistance.MGO is dispersed and evenly distributed in the coating,which can effectively improve the corrosion resistance of the water-based coating.In the water-based resin,it exists in the form of a large amount of cross-linking and a small amount of mechanical compounding.This compound mode can greatly enhance the intermolecular binding force and make the protection efficiency（PE）reach 99.7%.（3）Composite coating was prepared by using polyvinyl alcohol（PVA）to cure GO composite water-based epoxy resin.The use of glutaraldehyde（GA）further improves the crosslinking reaction of the composite coating.The results showed that:（1）PVA cured water-based coating has excellent flatness and corrosion resistance.（2）The cross-linking agent effectively improves the cross-linking effect of the coating and forms a complex cross-linked structure with GO and water-based resin.The molecular weight of the coating and the binding force between the molecules are increased,reducing the generation of coating defects,so that the composite coating has excellent corrosion resistance.The composite coating has the contact angle of 86°,the excellent self-corrosion voltage（0.41 V）and corrosion current(0.098μA/cm^-2).The protection efficiency of 99.99%.Therefore,studies have found that the use of coupling agents to modify corrosion inhibitor materials and improve the crosslinking reaction during curing are both effective ways to improve the corrosion resistance of composite waterborne epoxy resin coatings,and it is also effective technology to improve the corrosion resistance of waterborne coatings.