ESTUDO DE REVESTIMENTO HIDROFÓBICO SOBRE SUPERFÍCIE DE ALUMÍNIO (AA6061-T6) DAS HÉLICES DOS AEROGERADORES

Abstract

The production of electricity from the wind power source is attractive in environmental and economic terms, so much so that this form of energy has been studied with considerable attention over the last years. To optimize the production process of this, it is fundamental to provide greater efficiency in the generation of electricity. The wettability of the blades surface of the wind turbines is one of the characteristics of the energy production that can be optimized. In this sense, the objective of this work is to obtain a coating by the polymeric precursor method to be applied on aluminum propellers (AA6061 - T6) of aerogenerators, and characterize the wettability, corrosion in solution Sodium Sulphate, and the influence of Escherichia coli on the biodeterioration of the coating. In the present study, the preparation of the aluminum alloy surfaces and the best polymerization conditions of the coating were tested. Experimental design was used to test the proportion glycerin : citric acid (GA) 10: 1, 15: 1 and 20: 1 and residence in the kilns or not, the experimental planning response was obtained by measuring the contact angle - CA. From the planning answer, we chose to test other proportion (16: 1, 16.5: 1, 17: 1, 17.5: 1, 18: 1 and 19: 1). The chemical composition of the coating was analyzed by vibrational spectroscopy in the infrared region - FTIR. Polarization curves were obtained by applying potentials to the working electrode, immersed in the electrolytic solution Na2SO4 solution 0.5 mol L-1 pH4, to determine the corrosion protection efficiency of the coating. Pure strains of non-pathogenic E. coli ATCC 25922 were used for the biodeterioration study. The solutions used were PBS and Na2SO4, at pH 4 and pH 7 and exposure time of 1 day and 7 days. It was possible to obtain coatings having hydrophobic classification according to ASTM-D 7334 -08 (2013), the proportion GA 16: 1 which resulted in the highest contact angle of 83 ° ± 2 °. The coating according to the FTIR is a polyester having free hydroxyl groups. This coating inhibits substrate corrosion in 99.99% in Na2SO4 pH 4. In PBS and Na2SO4 medium pH 7, bacterial activity was observed on the coating, after which it was removed after 7 days. Indicating that the coating is susceptible to biodeterioration in E. coli saturated medium.