Advancing CFRP durability: Interfacial and weathering performance of epoxy and acrylic matrices

Abstract

This study investigates the enhancement of weather resistance in carbon fiber-reinforced plastic (CFRP) by controlling the polymer matrix, focusing on the effects of acrylic resin. As the application of CFRP expands across various industries, its durability in outdoor environments has become a critical factor for structural materials. The mechanical properties of the polymer matrix were evaluated through tensile and flexural tests, and it was found that acrylic resin exhibited approximately 15 % lower mechanical properties compared to epoxy resin. This difference was observed to result in reduced performance of acrylic-based composite materials under neat conditions. However, after UV exposure, acrylic-based CFRP was shown to resist yellowing and maintain its mechanical properties, whereas epoxy-based CFRP experienced a 16 % decrease. The surface of CFRP was analyzed using FE-SEM, and differences at the interface were identified: fiber exposure and damage were observed in epoxy-based CFRP, while only surface cracks occurred in acrylic-based CFRP. Surface energy analysis was conducted, and it was confirmed that UV degradation increased the dispersive component of epoxy-based CFRP due to exposed carbon fiber (CF). Surface analyses using XPS and FT-IR revealed changes in the chemical composition of the CFRP surfaces, with increased oxidation of epoxy-based CFRP after UV exposure, while the acrylic-based CFRP showed more stable surface chemistry. These findings suggest that acrylic-based CFRP can be utilized in applications requiring improved weather resistance and long-term stability. © 2025