Epoxy-layered silicate nanocomposites as matrix in glass fibre-reinforced composites

Epoxy-layered silicates nanocomposites based on diglycidyl ether of bisphenol A and an anhydride-curing agent have been successfully synthesised. A manufacturing process using hand lay-up, vacuum bagging, and hot pressing techniques was developed to produce glass fibre-reinforced laminates with this nanocomposite matrix. Transmission electron microscopy indicated that silicate layers dispersed in the epoxy matrix present a long-range order with an interlamellar spacing of about 9 nm. X-ray diffraction analysis confirmed this nanostructure both in the nanocomposites and in the fibre-reinforced composite based on the same matrix. Scanning electron micrographs of the laminate with a nanocomposite matrix showed that nanolayers are apparently sticking at the surface of the glass fibre, improving possibly in this manner the interfacial properties of the fibres. Flexural testing of the laminates showed that the nanolayers improve the modulus and the strength, respectively, by 6% and 27%. Dynamic mechanical analyses of the epoxy and nanocomposite plates and their corresponding laminates showed a systematic glass transition temperature decrease of the nanocomposite based materials. This explains probably the larger water uptake observed at 50 °C in the plate and the laminate based on a nanocomposite matrix as compared with those based on the pristine epoxy.