A corrosion inhibitor test for copper-based artifacts

A new quantitative corrosion testing procedure for copper and copper alloy corrosion inhibitors was developed, with the aim of calculating corrosion protection in percent for each inhibitor on trial. 2-aminopyrimidine, 2-amino-5-mercapto-1,3,4-thiadiazole, benzotriazole, 5,6-dimethylbenzimidazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptopyrimidine and 2-mercaptobenzothiazole were tested for their effectiveness in preventing the conversion of nantokite (copper (I) chloride, CuCl) into paratacamite (basic copper (II) chloride, CuCl 2 ·3Cu(OH) 2 ) which causes major damage in archaeological copper artifacts.