The role of fiber-matrix compatibility in vacuum processed natural fiber/epoxy biocomposites

Utilization of raw natural fibers is a research topic of interest for achieving low-cost and ecofriendly composite materials with properties including low density and high specific strength. In order to obtain materials with these properties, matrix-reinforcement characteristics should be taken into account, as well as the processing method. Therefore, the aim of this research is the production of epoxy resin biocomposites by using three natural fibers as reinforcement, which helped to stablish the role of compatibility and vacuum level in the material’s mechanical properties. Fique, Fique-cotton and Moriche fibers were molded with epoxy resin at different vacuum pressures, resulting in materials with tensile strengths of 50.7 ± 1.3 MPa and 31.5 ± 0.5 MPa for Epoxy/Fique and Epoxy/Fique-Cotton biocomposites processed under a vacuum pressure of 0.4 bar, respectively. The best result for epoxy/moriche biocomposites was 31.5 ± 0.5 MPa at 0 bar. This demonstrated the differences in fiber-matrix compatibility and that applying high vacuum is not necessarily beneficial for achieving high performance biocomposites, as it is commonly the case for composites manufactured with synthetic fibers.