Effect of seawater exposure on tensile and flexural properties of glass/epoxy composite

• Published in: Materials today : proceedings 2023, Vol.82, p.314-321
• Main Authors: Shrivastava, S.M., Ramarao, G., Buragohain, M.K., Selvaraj, N
• Format: Article
• Language: English
• Subjects: E-Glass/Epoxy composite; Flexural strength; Mechanical Property; Seawater Exposure; Tensile strength
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2023.02.143

In recent times, increasing and widespread usage of composite has become a necessity for aerospace, automobiles, and marine application due to its high specific strength and stiffness and it has attracted not only the necessity of retaining its mechanical properties under exposure to hostile environments but encouraged to explore the possibilities of barrier resin coating to reduce this degradation. This study examined the seawater exposure effect on the mechanical properties of E-glass/epoxy composite. The two varieties of test specimens namely bare and barrier resin-coated specimens were made as per the ASTM standard out of E-glass/epoxy composite laminate to evaluate its mechanical parameters and barrier resin-coated specimens were coated with the resin of varying thicknesses. These all type of specimens was immersed inside the seawater. Test results show that seawater exposure to test specimens has notably reduced their tensile and flexural properties as compared to as-received specimens. The seawater exposure has reduced the tensile strength by 24.09 %, 17.65 %, and 10.23 % in warp and 22.96 %, 15.47 %, and 8.37 % in weft direction for bare, with 0.1 mm and 0.2 mm resin coating, respectively. Similarly, flexural strength was reduced by 20.38 %, 12.75 %, and 9.93 % in warp and by 17.41 %, 10.85 %, and 9.80 % in weft direction for bare, with 0.1 mm and 0.2 mm resin coating, respectively as compared to as-received specimens. It was observed from SEM micrographs too, that bare specimens exhibited a reduction in properties due to the diffusion of seawater, which will be followed by a reaction of hydrolysis in the composite. It was illustrated that the test specimens with barrier resin coated, limit the seawater ingression. The optimum thickness of the barrier resin coating was derived from plotting the normalized parameter w.r.t thickness of the coating.