Mechanical properties of fibreglass and carbon-fibre reinforced polyetherimide after twenty years of outdoor environmental aging in the city of Gijón (Spain)

This paper reports the results obtained after carrying out tests on specimens of two types of composite materials. These materials have the same polyetherimide (PEI) thermoplastic matrix, but a different type of reinforcement. In both cases, the reinforcement is fabric, one being made of carbon fibre and the other, of fibreglass. The specimens were tested after various periods of exposure to an outdoor environmental aging up to a maximum period of 20 years. Following static characterization tests, a significant decrease in mechanical properties was observed during the first eight years of exposure. From that time onwards, once what could be called the aging limit has been reached, these properties were maintained. From the fractographic point of view, there is a substantial loss of surface resin. This loss of resin is much more pronounced in the fibreglass composite, even being accompanied by fibre breakage. •There is a substantial loss of matrix during the time of exposure.•The existence of a limit value due to aging was detected in the case of the different mechanical properties under study.•The decrease in the mechanical is substantially greater in the GFRP than in the CFRP.