Mechanical and EMI shielding performance of glass/carbon hybrid composites with cellulose-paper interleaves after cryogenic conditioning

This research assesses the mechanical and electromagnetic interference (EMI) shielding performance of cellulose-interlayered glass/carbon hybrid fiber-reinforced polymer (HFRP) composites at room temperature (RT) and cryogenic (−196°C) conditions. Symmetric [GC]₂[CG]₂ and [CG]₂[GC]₂ arrangements were constructed. Mechanical testing demonstrated that augmenting the density of the cellulose interfaces markedly enhanced flexural performance, while concurrently resulting in a drop of tensile strength by as much as 23% owing to the development of weaker interlayers. Bending tests revealed that all-plane interleaving enhanced strength from 215 to 250 MPa for G/C and from 226 to 335 MPa for C/G; in cryogenic conditions, the flexural strength of C/G reached a maximum of 340 MPa. Additionally, all composite variations exceeded the 30 dB commercial reference value for EMI shielding effectiveness, while the cryogenically processed all-plane C/G laminate reached a SE_Tot peak of 63 dB. The protective mechanism was mostly absorption-based (∼80%), augmented by the porosity configuration of the cellulose fibers and cryogenically produced micropores that facilitate repeated internal reflections. The results confirm the multifunctional efficacy of sustainable cellulose interlayers for high-performance applications under harsh conditions.