Thermo-mechanical and flexural behavior of composite laminates remanufactured with recycled basalt fiber fabrics

Abstract

This work reports the basalt fiber (BF) recycling process via 50 wt.% hydrogen peroxide (H₂O₂) assisted by solvolysis at low temperature (∼75°C) from a virgin basalt fiber reinforced polymer (BFRP) laminate and the remanufacturing of recycled BFRP composites by the vacuum assisted resin infusion. To evaluate the surface state of the recycled BF, morphological analysis and elemental composition were performed using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). SEM imaging demonstrated that the surface of recycled BF exhibits morphological changes, EDS analysis confirms an increase in oxygen content compared with virgin fibers and no change in fiber orientation was observed after the solvolysis process. After that, beam-type specimens were obtained from recycled BFRP laminates to evaluate their fiber volume fraction, thermo-mechanical, and flexural properties. The experimental results were compared with the virgin BFRP composites and showed that the fiber volume fraction and flexural modulus suffered an 11% and 13% decrease, respectively. However, the recycled BFRP composite had an increase of 28% in flexural strength due to the surface modification of basalt fibers during the solvolysis process with H₂O_2, which increased surface roughness and mechanical interlocking, and no significant change in the glass transition temperature was observed. The recycling process results showed that the recovered BF from the virgin BFRP composites maintain their original woven configuration and can be reused to manufacture new composite laminates, thus promoting the circular economy.