Titanium dioxide performance in polyethylene teraphthalate protective coatings on electrolytic chromium coated steels

The present study analysed the behaviour of titanium dioxide (TiO₂) in polyethylene teraphthalate (PET) polymer coatings on electrolytic chromium-coated steel (ECCS) plates employed in the manufacturing of food containers. Also, the thermal source affecting rutile distribution in PET coatings was determined; i.e. whether it originated in the manufacturing processes and treatments of the composite to allow coextrusion and PET adherence on steel, or was rather a consequence of industrial canning processes. Measurements at parallel intervals from the surface to the metal interface were made by Raman and microRaman vibrational spectroscopy techniques to characterise the rutile distribution in the PET thickness. Finally, scanning and transmission electron microscopy observations determined the changes on the surface properties of the coating and provided information on the chemical and structural changes undergone by the polymer protective coating, which affect the performance and the protective capacity of polymers in contact with canned foods.