Enhanced properties of surface-modified carbon fiber reinforced epoxy composites

Abstract

The enhancement of epoxy composites has emerged as a captivating area of research in recent years, particularly in addressing the critical challenge of filler debonding within the epoxy matrix. This study explores the use of chemically oxidized carbon fibers (CFs) as a reinforcing agent to significantly improve the thermal and mechanical properties of epoxy composites. The oxidation process increases the surface functional groups on CFs, facilitating better interaction during curing. Our findings reveal a remarkable 32% increase in tensile strength and a 28% increase in modulus strength when comparing molded composites of pristine and oxidized CFs. Furthermore, interlaminar shear strength analysis demonstrates a striking 92% improvement in adhesion properties, rising from 30.4 MPa for pristine CFs to 58.3 MPa for oxidized CFs. Thermal gravimetric analysis indicates a substantial enhancement in thermal stability for the epoxy/oxidized CFs composite. Notably, the fracture mode transitions from adhesive failure in pristine CFs to cohesive failure in the oxidized variants. This paper presents a straightforward and effective strategy for modifying CFs, paving the way for the development of advanced composites with superior thermal and mechanical properties. © The Author(s) 2025