Seawater ageing of thermoplastic acrylic hybrid matrix composites for marine applications

Increasing usage of polymer composite materials necessitates the development of recyclable alternatives to traditional thermoset matrices or new techniques for recycling these materials. One family of promising recyclable matrices are the room temperature infusible acrylic resins, known commercially as Elium®. If these new materials are to be used in the tidal stream energy and shipping sectors, they must be able to withstand long-term immersion in seawater without significant losses in mechanical properties. In this study, accelerated seawater ageing is applied to acrylic/glass fibre and modified acrylic/glass fibre composites along with a traditional epoxy/glass fibre baseline. The mechanical properties (tensile, flexural, and short beam) are compared before and after ageing, and electron microscopy is used to examine fracture surfaces to determine the effects of water ingress on fracture propagation. In addition, the diffusion coefficients of the composites in seawater are compared and the changes in glass transition temperatures are used to determine the effects of plasticisation.