Epoxy Resin Biocomposites Reinforced with Flax and Hemp Fibers for Marine Applications

A broader application of biocomposites still faces many challenges regarding structural integrity, environmental resistance, and biodegradability. These issues are particularly important when their marine applications are considered. Therefore, this paper seeks to address the hygroscopicity, mechanical properties, and biofouling resistance of biocomposites made of epoxy resin with 28 m% bio-based carbon content reinforced with flax and hemp fibers. A series of experiments are performed to acquire water absorption rates, saturation limits, mass increase, tensile and flexural properties, interlaminar shear strength, impact resistance, and mass gain due to biofouling. All tests of mechanical properties are conducted before and after immersion in seawater. The acquired saturation limits of flax/epoxy and hemp/epoxy biocomposites amount to 7.5% and 9.8%, respectively. The water uptake causes the tensile and flexural properties to decrease by 26-74%, while interlaminar and impact strength increase for flax/epoxy and decrease for hemp/epoxy biocomposites. In addition, it is observed that in almost all cases, flax/epoxy has superior properties compared with hemp/epoxy biocomposites. It is expected that this research will motivate naval architects and classification societies to consider biocomposites as prospective hull materials that provide both structural integrity and environmental sustainability.