Fracture toughness and properties of epoxy / polyurethane blend matrix reinforced with natural fiber

In this work, binary blends of epoxy resin (EP) and different proportions of polyurethane (Pu) (0%, 5%, 10%and 15%) were prepared. Vacuum infusion was used to manufacture the laminate of the composite containing natural fiber. These fibers are: flax woven fiber (F), wool woven fiber (W), and jute woven fiber overlapped with unidirectional flax (JF) arranged as Intra-yarn. The flax and wool woven fiber are arranged by two different angle orientations and hybrids. Tensile and fracture toughness tests, according to ASTM-D5045, were evaluated. ANSYS workbench was used to check the results. the investigating results showed that increasing the percentages of polyurethane into blends increased ductility and reduced modulus of elasticity, yield stress, and fracture toughness. The mechanical properties were improved and the fracture toughness of wool composites was increased by 108.878 % and 70.122 % respectively when hybridized by flax and jute/ flax woven fiber.