Stability of polyester- and vinyl ester-based composites in seawater

Glass fiber-reinforced polymer composites are used in boats, yachts, ships, submarines and offshore drilling platforms due to their low cost, high specific strength, fatigue endurance and durability [1-6]. However, a problem with fiberglass laminates is their low Young's modulus, which makes it difficult to build ultralight marine structures with adequate stiffness. Consequently, marine composite structures requiring high stiffness are often built using carbon fiber composite. However, little published information is available on the effect of long-term seawater immersion on carbon fiber composites [4, 7]. Therefore, the aim of this research is to compare the stability of glass and carbon fiber composites in seawater. The materials studied are glass/polyester, carbon/polyester, glass/vinyl ester and carbon/vinyl ester, and these are representative of composite materials used in boats, yachts, ships, submarines and offshore drilling platforms.