Degradation of glass fiber-reinforced plastic composites containing nanoclay in alkaline environment

The durability of glass fiber-reinforced plastic (GFRP) composites made from neat epoxy and organoclay nanocomposite in the alkaline environment is studied. Accelerated tests are performed by immersing the composite plates in the alkaline solution at 60°C. The tensile test and dynamic mechanical thermal analysis test are performed to evaluate the residual tensile properties and thermo-mechanical properties of aged GFRPs, while Fourier transform infrared spectrometry, micro-indenter, and scanning electron microscopy are employed to characterize the deterioration of the matrix, fiber, and fiber–matrix interface in GFRPs. The tensile properties and storage modulus of the GFRP composites are reduced with increasing aging time. Interestingly, the reduction is significantly mitigated when the organoclay nanocomposite is used as the matrix material. Degradation of matrix material, weakening of fiber–matrix interfacial bonding, and corrosion of glass fibers contribute to the property reduction in both composites. The excellent barrier characteristics of organoclay in the matrix are responsible for the superior performance of the GFRPs made from nanocomposite matrix, which in turn reduces the degree of corrosion of glass fibers.