Relevance of biofilms for the biodeterioration of surfaces of polymeric materials

Deterioration of polymeric materials is caused by adhering microorganisms that colonize their surfaces, forming biofilms; thus, biodeterioration is a biofilm problem. Biofilms consist of microorganisms embedded in a polymer matrix, attached to surfaces of all kind. Structure and function of synthetic polymeric materials can be damaged by biofilms in various ways, among these: (1) by coating the surface, masking surface properties and contaminating adjacent media such as water by released microorganisms; (2) by increasing the leaching of additives and monomers out of the polymer matrix by microbial degradation; (3) by attack by enzymes or radicals of biological origin to polymer and additives; leading to both embrittlement and loss of mechanical stability; (4) by accumulating water and penetrating the polymer matrix with microbial filaments, causing swelling and increased conductivity; and (5) by excretion of lipophilic microbial pigments that lead to unwanted colours in the polymer. Direct and indirect damage as caused by these five mechanisms can be very high. (C) 1998 Elsevier Science Limited. All rights reserved.