CORROSION PROTECTION OF TIN USING CARBOXYLATE COATINGS IN A SODIUM CHLORIDE SOLUTION

Tin is a moderately corrosion resistant material that is widely used in tinplate for food and beverage packaging. However, despite its moderately corrosion resistance, the presence of oxidizing agents enhances tin dissolution. The dissolution of metallic tin, especially from the inside of a can body into the food content, has a major influence on the food quality and may cause toxicological effects. To overcome the problem, different chemical compounds are added. The most utilized inhibitors in the food industry are nitrites and nitrates, which are hazardous to human health. The present study aims to investigate the influence of carboxylic acids on the corrosion resistance of tin, since they are present in fruit juices and different foodstuffs. The corrosion protection efficiency of carboxylate coatings is investigated in a sodium chloride solution using electrochemical and spectroscopic techniques. The structural characteristics of the surface coatings are investigated using Fourier transform infrared spectroscopy and optical microscopy.