Marine anti-corrosion paints based on thiouracil compounds

The inhibition of marine corrosion of steel by 6-amino-2-thiouracil (I) and its derivatives 6-benzylideneamino-2-thiouracil (II) and 6-p-chlorobenzylideneamino-2-thiouracil (III) has been tested on laboratory scale using electrochemical technique which was performed on mild steel in sea water medium and on field scale through the incorporation of the compounds individually in marine paints compositions. The paints containing the compounds were applied on unprimed steel and the coated panels were tested in Alexandria Eastern Harbour water (Egypt). The electrochemical measurements indicated that both compounds (I) and (III) acted as cathodic-type inhibitors, but the data of compound (II) showed neither cathodic nor anodic inhibition. Two marine paint compositions were prepared using different binder materials. The three compounds were added individually in both paint compositions. The paint composition based on the soluble resin material as a sole binder and containing compound (I) showed the best corrosion protection of its steel surface till more than two months followed by the paint composition containing compound (III). The same paint containing the compounds showed antifouling property for four months.