Effects of harsh weather and seawater on glass fiber reinforced epoxy composite

Abstract

The lack of reliable engineering data on the durability of glass fiber reinforced Epoxy (GFRE) pipes when exposed to harsh Arabian Gulf outdoor environment has limited their wide use for saltwater and crude oil handling and transportation. This article explores the combined effect of natural and accelerated weathering and seawater on tensile properties of GFRE pipe materials. Saltwater filled pipes were exposed to outdoor environment in Dhahran, Saudi Arabia for periods ranging from 6 to 12 months. Ring-shaped tensile test specimens were also immersed in oxygenated saltwater at room temperature for time periods ranging from 300 to 10,000 h. The natural exposures resulted in gradual reduction of tensile strength and fracture strain with exposure time in saltwater filled pipes. The exposure to oxygenated saltwater immersion also showed detrimental effects after 300 h of exposure. Longer immersion periods did not result in further strength degradation. The stiffness of the GFRE pipe specimens remained more or less unaffected by exposure to seawater. Fractographic analysis of unexposed specimens showed a combination of Mode I and Mode II failure characterized by inclined hackles as well as fiber breakage. High outdoor temperature and moisture absorption decreased fiber—matrix interface strength and caused degradation at the fiber level resulting in lower ultimate strength, fracture strain, and stiffness of the GFRE.

Performance of Composite Materials Subjected to Salt Water Environments

“…Figure 4 shows the weight gain for epoxy samples conditioned at 40°C, and indicates that the [0] 2 samples are approaching an equilibrium moisture content at 1000 hours. However, the thicker samples [0] 6 have lower moisture absorption and have not reached saturation. Initial testing protocol was to remove sample after 1000 hrs at 40°C and store in synthetic sea water at…”

Effect of Accelerated Weathering on Tensile Properties of Kenaf Reinforced High-Density Polyethylene Composites

“…However, the most possible cause of deterioration of the K-HDPE composite was due to the effect of high humidity produced from water vapour inside the accelerated weathering chamber. Hydrophilic kenaf fibres attract water molecules into the K-HDPE composite and cause fibre-matrix debonding (Merah et al, 2010). As the exposure time increases, the moisture creeps deeper into the K-HDPE composite creating more fibre-matrix debonding, which decreases the tensile strength of the composites (Figure 6).…”

“…One major advantage of kenaf fibres for biocomposites is that it has the appearance of wood but possesses plastic processing properties, which means it can easily be fabricated like other plastic products. These so-called environmentally friendly composite materials have been developed into numerous applications both for indoor and outdoor use (Misri, Leman, Sapuan, & Ishak, 2010;Maleque, Belal, & Sapuan, 2007;Merah, Nizamuddin, Khan, Al-Sulaiman, & Mehdi, 2010;Rowell & Stout, 2007). However, biocomposite materials intended for outdoor applications are exposed to weather elements that deteriorate the integrity of the composite's mechanical properties (Maleque et al, 2007;Merah et al, 2010;Pritchard, 2000;Brennan & Fedor, 2006).…”

Effect of water and crude oil on mechanical and thermal properties of epoxy-clay nanocomposites

“…Therefore, epoxy resin is one of the most applied thermoset polymers as a matrix for glass fiber reinforced pipes (GFRP) and anticorrosion coatings. However, it is observed that liquid uptake degrades the functional, structural, and mechanical properties of epoxy‐based composites . Water absorption in polymer structures is related to the existence of molecule‐size holes and the affinity between polar groups of polymers and water .…”