Dynamic mechanical analysis of the seawater treated glass/polyester composites

Glass fibre/unsaturated polyester composites were produced by using the VARI (vacuum assisted resin infusion) technique. The fabricated four-layer specimens were treated by seawater for various periods of time. A decreased trend of the tensile strength with prolonged treating time was noticed. DMA (dynamic mechanical analysis) technique was employed to investigate the matrix degradation and interfacial debonding of the seawater treated specimens. The gradually decreased Tg (glass transition temperature), E′ (storage modulus), and the increased tan δ (energy dissipation) with extended treating time indicated that both the matrix and the interface had been deteriorated by the seawater.