Effect of moisture absorption on mechanical properties of bio-epoxy and recyclable bio-epoxy for aerospace application

In recent years, bio-based epoxy has gained significant attention for use in fiber-reinforced composite materials and structures, particularly in the aerospace industry, which is increasingly focused on sustainability. Consequently, it is crucial to study bio-based epoxies, perform material characterization, and compare their behavior with conventional epoxies. This study aims to determine the effect of moisture on the mechanical properties of three bio-based epoxies: two non-recyclable and one recyclable. Four different types of tests were conducted, namely, tensile, compression, bending, and fracture toughness tests. The results indicate that the recyclable bio-epoxy exhibits lower moisture absorption at 2.3% compared to the non-recyclable bio-epoxy. Recyclable bio-epoxy shows excellent fracture toughness, which is the main criteria for a resin when it is used as a composite matrix in aerospace, with a fracture toughness K _IC of 2.5 MPa.m ^0.5 . This result suggests its high potential as a viable alternative in aerospace.