PROTECTION OF LEAD STORED IN MUSEUM STORAGE CABINETS AGAINST CORROSION BY MEANS OF VAPOUR PHASE CORROSION INHIBITORS

High sensitivity of lead to organic compounds leads to degradation of lead artifacts stored in the museums or archives together with organic materials (wood, glue, leather, paper, plastic, etc.). Protection of the lead stored under adverse conditions (environment polluted by organic compound, mainly acetic acid) is based on the use of corrosion inhibitors. The aim of this work was to test compounds with high tendency to sublime under atmospheric conditions and good ability to form a protective polymeric layer on the lead surface. The effect of volatile corrosion inhibitors mentioned in the literature (benzotriazole, cyclohexylamine carbonate, dicyclohexylamine nitrite, urotropine and sodium benzoate) was tested directly by weight loss measurement and by the resistometric method in humid atmosphere with various acetic acid vapour concentrations. The damage of lead was characterized by X-ray diffraction analysis and scanning electron microscopy. The greatest inhibition efficiency in all corrosive atmospheres and for non-treated and corroded lead samples was achieved by cyclohexylamine carbonate.