Evaluación del biodeterioro fúngico de pinturas anticorrosivas mediante técnicas electroquímicas

S. ROSELLI; C. DEYÁ; R. ROMAGNOLI; N. BELLOTTI

Concepción

Congreso; 15º Congreso Internacional en Ciencia y Tecnología de Metalurgia y Materiales, CONAMET / SAM; 2015

SAM - CONAMET

Biodeterioration caused by the vital activity of microorganisms becomes more important when it takes place onto metal structural materials which are part ofbridges, pipes, roofs, etc. due to their economic, social and cultural significance. Biodeterioration, in many cases, is the result of the activity of microbialcommunities mostly integrated by fungi, bacteria and algae. Filamentous fungi, abundant in these biofilms, released, among other products, organic acids intothe surrounding, which can cause corrosion of metal substrates. Corrosion influenced by fungal growth can be defined as an electrochemical process involvingfungi. Therefore, the objective of this work is to use electrochemical techniques (corrosion potential and ionic resistance) to study the biodeterioration of someanti-corrosive coatings. At first, fungal isolates were obtained from biodeteriorated paint films following routine microbiological techniques. The selectedisolates (Aspergillus and Penicillium) were used to inoculate the experimental coatings to be evaluated. Paints with different experimental anticorrosivepigments (zinc phosphate and modified zeolite with rare earth ions) were assessed. A paint without anticorrosive pigment was used as blank. The inoculatedsamples and corresponding controls were placed in containers with regulated humidity conditions. After two months electrochemical measurements were madeand results showed that the electrochemical techniques employed are useful to differentiate fungal degrading activity on the anticorrosive paints tested.