Avaliação do envelhecimento ambiental do compósito polimérico na Estação de Tratamento de Efluentes do Sistema Central de Natal - RN - Brasil

Abstract

The use of composites presents a structural alternative that provides mechanical advantages when compared to more traditional building materials such as concrete and steel. Polymer composites, when exposed to adverse conditions such as ultraviolet radiation, high temperatures, oxidizing agents and excessive moisture, result in changes in physical characteristics and in their mechanical behavior, depending on the period of exposure and the conditions of service. Thus, the present work presents an evaluation of the mechanical and physical behavior of the fiber glass type E reinforced polymer composite (FGRP) when exposed to agents of environmental aging at the effluent treatment plant of the Central System of Natal-RN, also known as ETE do Baldo. The composite was made by the hand lay-up method and the test bodies (TB) according to ASTM D3039-14 and ASTM D790-10 standards for the uniaxial tensile and three-point bending tests, respectively, where these were exposed for a period of 08 (eight) months, conditioned above and immersed in the effluent. In addition, the physical-chemical characterization of the effluent was carried out to evaluate the following parameters: pH, conductivity, sulfate, alkalinity, acidity, sulfide and temperature, aiming at characterizing the effluent conditions in direct and indirect contact with the composite. After the exposure period, tests were carried out for morphological evaluation, evaluation of the structural integrity, evaluation of the mechanical performance and of the characterization of the fracture of the polymer composite, and thus a comparison was made between the mechanical characteristics of the fracture of the polymer composite in the original state with that of the aged state (post exposure in ETE). The polymer composite studied proved to be stable after the aging period with little variation of mass and slight changes in its coloration. The mechanical properties evaluated also did not have significant changes during the studied period, thus showing that the FGRP presents the potential of being used in aggressive environments such as in effluent treatment plants.