Abstract:The gradual replacement of conventional materials with composite materials has become a concern due to their response to adverse environmental conditions, such as ultraviolet radiation, high temperature, and humidity. In this context, composite laminate using ortho-terephthalic polyester resin as matrix, reinforced with two layers of unidirectional woven licuri fiber, was submitted to accelerated environmental aging in order to study the influence of environmental degradation on mechanical properties, morpholo… Show more
“…And this crack also causes lack of adhesiveness in the fiber/matrix interface. According to Leão et al., 28 the surface deterioration caused by environmental aging in the polymer–matrix composites causes dimensional variations like reinforcement exposition, crack formation, as well as appearance of micro and macro fractures in the matrix, similar damages to those found in this study. Figure 13.Surface of test specimen after aging four months immersed in effluent.…”
This paper presents an evaluation of the mechanical and physical behavior of the type E glass fiber-reinforced polymeric composite when exposed to environmental aging agents in an effluent treatment plant. The composite was made by the hand layup process, and the test bodies were made according to the American Society for Testing and Materials standards D3039-14 and D790-10 for the uniaxial tensile and three-point bending tests, respectively, where they were exposed for a period of eight months, conditioned above and immersed in the effluent of the treatment plant. The physicochemical characterization of the effluent was evaluated considering the following parameters: pH, conductivity, sulfate, alkalinity, acidity, sulfide, and temperature, aiming to characterize the effluent conditions in direct and indirect contact with the composite. After the exposure period, tests were carried out for morphological evaluation, structural integrity evaluation, mechanical performance evaluation, and fracture characterization of the polymer composite, thereby leading to a comparison of the mechanical characteristics in the original state to that of the aged state (after exposure in the effluent treatment plant). The polymeric composite studied was stable after the aging period, with little mass variation, less than 0.5%, and slight changes in color. The mechanical properties evaluated also did not change significantly during the study period. Variations in uniaxial tensile strength were less than 1.4% and for three-point bending less than 10%, thus showing that the type E glass fiber-reinforced polymer composite has potential for use in harsh environments such as in effluent treatment plants.
“…And this crack also causes lack of adhesiveness in the fiber/matrix interface. According to Leão et al., 28 the surface deterioration caused by environmental aging in the polymer–matrix composites causes dimensional variations like reinforcement exposition, crack formation, as well as appearance of micro and macro fractures in the matrix, similar damages to those found in this study. Figure 13.Surface of test specimen after aging four months immersed in effluent.…”
This paper presents an evaluation of the mechanical and physical behavior of the type E glass fiber-reinforced polymeric composite when exposed to environmental aging agents in an effluent treatment plant. The composite was made by the hand layup process, and the test bodies were made according to the American Society for Testing and Materials standards D3039-14 and D790-10 for the uniaxial tensile and three-point bending tests, respectively, where they were exposed for a period of eight months, conditioned above and immersed in the effluent of the treatment plant. The physicochemical characterization of the effluent was evaluated considering the following parameters: pH, conductivity, sulfate, alkalinity, acidity, sulfide, and temperature, aiming to characterize the effluent conditions in direct and indirect contact with the composite. After the exposure period, tests were carried out for morphological evaluation, structural integrity evaluation, mechanical performance evaluation, and fracture characterization of the polymer composite, thereby leading to a comparison of the mechanical characteristics in the original state to that of the aged state (after exposure in the effluent treatment plant). The polymeric composite studied was stable after the aging period, with little mass variation, less than 0.5%, and slight changes in color. The mechanical properties evaluated also did not change significantly during the study period. Variations in uniaxial tensile strength were less than 1.4% and for three-point bending less than 10%, thus showing that the type E glass fiber-reinforced polymer composite has potential for use in harsh environments such as in effluent treatment plants.
“…Displacement at the fiber/resin interface may occur due to the development of osmotic pressure pockets on the fiber surface due to the leaching of water soluble substances from the fiber surface. In this way, the degradation of the composite occurs not only by the degradation of the individual constituents, matrix and fiber, but also due to the loss of the interaction between them [7].…”
The search for new composites that use natural fibers as reinforcement has driven the study of the vegetal fibers they are renewable, biodegradable, low cost and cause low environmental impact. Licuri fiber is obtained from the leaves of the Syagrus Coronata palm tree and possesses sufficient malleability to be woven. However, this type of material is subject to changes in mechanical behavior as a consequence of the natural degradation, mainly to those due to moisture absorption that can cause irreversible structural damage. In this sense, the present work sought to make an analysis of the influence of moisture on the mechanical performance of a unidirectional composite laminate of polyester matrix reinforced with licuri fibers. The composite laminates were manufactured by the by hand lay-up process. Water absorption, Uniaxial tensile and Three-point bending tests were perfomed according to ASTM D 570-98, ASTM D 3039-08 and ASTM D 790-07 standards, respectively. The results obtained on tests with composite in saturated state when compared to the tests with composite in the dry state (literature data) have shown that the polyester matrix composite reinforced with natural licuri fibers has its mechanical properties reduced by around 27% when exposed to moisture, as a confirmation of the hydrophilic nature of plant fibers.
“…É importante destacar que o aumento da resistência à tração dos laminados com Fibra de Vidro ocorre devido ao fato de as Fibras de Vidro serem mais fortes e rígidas do que as fibras de juta. Por fim, autores concluíram que por incorporação de fibras naturais e tradicionais contínuas no polímero, as propriedades mecânicas obtiveram melhora.ConformeLeão et al (2015) na tese, Accelerated environmental aging effects in structural integrity of licuri fiber reinforced plastics, foram analisados efeitos do envelhecimento de uma fibra natural nas propriedades mecânicas de um plástico reforçado por fibra de licuri. Para estimar tais efeitos da degradação do material orgânico foram realizadas análises microscópicas da microestrutura do material, bem como sua perda de massa.…”
O presente trabalho tem como objetivo comparar propriedades mecânicas de um compósito feito a partir de fibra de juta e manta de fibra de vidro com outros compósitos de configurações distintas existentes na literatura, como por exemplo a fibra de Licuri, fibra do bagaço da cana de açúcar entre outras. O processo de fabricação utilizado foi o Hand Lay-up, sendo a placa com a configuração: fibras de juta (± 90º), fibras de juta (± 90º), manta de fibras de vidro-E, fibras de juta (± 90º) e fibras de juta (± 90º). Os corpos de prova do material compósito foram fabricados e depois foram realizados ensaios de tração, a fim de avaliar suas propriedades para realizar o comparativo prático e teórico das características mecânicas do material. Os valores de resistência apresentados indicam a utilização de laminados híbridos em elementos estruturais de média dimensão, sendo por isso, adequados para próteses/órteses.
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