Dimensional stability, density, void and mechanical properties of flax fabrics reinforced bio-phenolic/epoxy composites

Due to the growing trend to promote alternative materials, the use of cellulosic fibers as filler/reinforcement in polymer composites has increased in popularity. The objective of this research is to determine the effect of flax fabric loading on the physical and mechanical properties of bio-phenolic/epoxy composites. The composites were fabricated using hand lay-up method in a mould and cured using a hot press. Bio-phenolic/epoxy blend was fabricated as control. The sample was tested for physical, tensile, flexural, impact and morphological properties. The result showed that, increasing the flax fabric loading has increased the water absorption and density of composites. The highest water absorption density was shown by the composite with 50 wt% flax fabric loading which is 3.73% and 1.23 g/cm³. In addition, there is no significant difference in void content for all composites. Moreover, the incorporation of flax fabric as reinforcement has improved the mechanical properties of composites. According to the morphological analysis results of the experiments, there was a good bonding interaction between the flax fabric and bio-phenolic/epoxy. The highest tensile strength, tensile modulus and impact strength was shown by composite with 50 wt% flax fabric which was 105.04 MPa, 9.10 GPa and 11.94 kJ/m² respectively while composite with 40 wt% showed the highest flexural strength and modulus which was 150.45 MPa and 8.4 GPa respectively. It was concluded that, bio-phenolic/epoxy blend reinforced with 50 wt% flax fabric showed the best overall mechanical properties and it will be used in the future study to fabricate carbon/kevlar/flax reinforced bio-phenolic/epoxy for ballistic helmet application.