Effects of UV-C exposure on composite materials made of recycled carbon fibers

Carbon fiber-reinforced polymers are widely used in space applications since they combine outstanding mechanical properties with low material density. However, the development of composite components involves raw materials that are becoming increasingly scarce and contributes significantly to carbon emissions during the manufacturing process. Indeed, the fabrication of fibers is energy-intensive and requires very high temperatures, high costs, and usually precursor materials derived from fossil fuels. In addition to the negative environmental impact due to the manufacturing process, there are critical issues related to the disposal of components fabricated using carbon/glass fiber composites. Therefore, the use of efficient recycling strategies becomes necessary, according to economic reasons and legislation. The recycled fibers exhibit different properties from virgin fibers, generally lower, due to adverse effects of the current recycling methods. In this study, we investigated the potential application of recovered carbon fibers in satellite platforms, using recycled fibers from our laboratory obtained with a subcritical solvolysis method that we have previously developed. Composite materials reinforced with recycled and virgin carbon fibers were exposed to UV-C, and the effects of irradiation were analyzed in terms of structural performance, surface morphology, and chemical modifications of the samples. Results were used to evaluate the possibility of effectively using recycled fibers in space applications, without significant loss of performance.