Basalt fibers as a sustainable and cost-effective alternative to glass fibers in sheet molding compound (SMC)

The focus of this study is to explore the feasibility of using basalt fibers (BF) as a potential sustainable alternative to glass fibers (GF) in sheet molding compounds (SMC) to reduce the weight and cost of conventional GF SMC. The interfacial interactions for BF/epoxy and GF/epoxy composites were assessed through single fiber fragmentation tests. The mechanical properties, including tensile and flexural modulus and strength, impact strength and thermomechanical properties for 25 wt% BF/epoxy composites made using SMC were determined and directly compared to 25 wt% GF/epoxy SMC composites. As indicated by the single fiber fragmentation tests, the two composites had similar interfacial shear strength (IFSS) and consequently similar adhesion at the fiber-epoxy interface. In addition, no distinguishable differences were found in the curing behavior of the two SMC composites. The storage modulus of the 25 wt% BF/epoxy composites was found to be higher than that of 25GF/epoxy in the glassy state. Moreover, the average tensile and flexural properties (both absolute and specific values) of the 25 wt% BF/epoxy SMC composites were higher or at least equal to those of 25 wt% GF/epoxy SMC composites. No difference in the impact strength of the two composites was recorded considering the statistical variation. In general, BF/epoxy SMC composites showed better or equal mechanical performance compared to GF/epoxy SMC composites suggesting that BF may be an alternative to GF with the potential to lead to lower cost SMC composites.