Biocorrosion and biofouling in carbon steel submerged in port polluted water of the Caribbean Sea: prevention and protection by means of antifouling coatings

The elevated degree of pollution and the high temperature of a port located in tropical latitude facilitate, in one first stage, the microbial colonization (slime film) of the metallic surfaces and later the intense fixation by epibiosis of macro organisms (biofouling) of characteristics very varied. In the present work several marine protective systems with characteristics anticorrosive / antifouling were evaluated in real conditions of field and laboratory with the purpose of eliminating the inorganic and biological corrosion in the underwater ship hulls, off-shore structures, etc. In this study, several anticorrosive primers systems were manufactured and tested; they were based on tripigmented compositions (lamellar zinc, extenders and corrosion inhibitors). The products of the corrosion were characterized by means of diffraction of X rays and by dispersion of energy of X rays as well as with optical observations and scanning electronic microscopy. In accelerated tests of laboratory, primers exhibited an excellent resistance to the corrosion and to the blisters formation. Finally and after characterizing biofouling of the experimental area, several soluble matrix antifouling compositions were formulated and elaborated in laboratory as finishing layer; the last ones showed in stationary state of dissolution a biocide-leaching rate superior to the critical value, which means an excellent control of biofouling fixation for at least 16 months in seawater immersion.