No abstract

This article investigates and compares the effects of hydrothermal aging on carbon fibre / Elium™ thermoplastic composite and on carbon fibre / vinylester thermoset composite for marine application. Accelerated aging tests are performed by immersion in deionised water at 70 °C.Water diffusion, monitored by regular weighing, shows that both composites as well as Elium™ resin exhibit non-Fickian behaviour. Analytical models are proposed to fit the experimental curves and to identify and compare diffusion parameters. The aging effects on the microstructure are evaluated using SEM, while irreversibility of degradation mechanisms is investigated by desiccation tests. Mechanical tensile tests, performed before and after aging, show the slight impact of water on tensile modulus and tensile strengths for both materials. Furthermore, it was found that shear modulus and interlaminar shear strength undergo significant alteration related to irreversible physicochemical degradation of the matrix. Studied materials have shown different diffusion behaviours, but similar mechanical properties evolutions.

This work aims at evaluating the durability of a carbon fibre reinforced thermoplastic composite under different aging conditions. The absorption and desorption of deionised water in carbon fibre (CF) reinforced Elium composite material were measured gravimetrically over two different temperatures. Water uptake experimental data were fitted to a Langmuir type diffusion model in order to identify and compare diffusion parameters and kinetics and to evaluate their dependence to aging conditions. It was found that the temperature increase had a significant effect only on saturation water uptake. Water desorption after aging was modelled accurately using Fick’s law and slight differences were found between model parameters. The effect of hydrothermal aging conditions and their reversibility were then evaluated by static and vibratory mechanical analysis. Results showed a slight and quasi-reversible reduction of longitudinal properties compared to shear properties at moderate aging temperature. While for higher aging temperature, the impact was found to be more significant and permanent on mechanical in-plane properties. Furthermore, static and modal results are confirmed by dynamic mechanical analysis, where the behaviour of studied material is differently affected by aging temperature, with a considerable increase in dried materials glass transition temperature.