Mechanical Behavior of CFRP Laminates Manufactured from Plasma-Assisted Solvolysis Recycled Carbon Fibers

The mechanical behavior of carbon-fiber-reinforced polymer (CFRP) laminates manufactured using plasma-assisted solvolysis recycled fibers was evaluated experimentally through a comprehensive mechanical testing campaign. The plasma-assisted solvolysis parameters were selected based on an earlier sensitivity analysis. Prepregs made from both virgin and recycled carbon fibers were fabricated via a hand lay-up process and manually stacked to produce unidirectional laminates. Longitudinal tension tests, longitudinal compression tests, and interlaminar shear strength (ILSS) tests were performed to assess the fundamental mechanical response of the recycled laminates and quantify the retention of mechanical properties relative to the virgin-reference material. Prior to mechanical testing, all laminates underwent ultrasonic C-scan inspection to assess manufacturing quality. While both laminate types exhibited generally satisfactory quality, the recycled-fiber laminates showed a higher density of defects. The recycled laminates preserved around 80% of their original tensile strength and maintained an essentially unchanged elastic modulus. Compressive strength was more susceptible to imperfections introduced during remanufacturing, with the recycled laminates exhibiting roughly a 14% decrease compared with the virgin material. On the contrary, the compressive modulus was largely retained. The most substantial reduction occurred in ILSS, which dropped by 58%. Overall, the results demonstrate that plasma-assisted solvolysis enables the recovery of carbon fibers suitable for remanufacturing CFRP laminates, while the observed reduction in mechanical properties of recycled CFRPs is mainly attributed to defects in manufacturing quality rather than to intrinsic degradation of the recycled carbon fibers.