Tensile and flexural properties of epoxy-date palm fiber composites

In this research trunk fibers of date palm tree were utilized as the reinforcement for epoxy matrix composites. Composite samples were produced using the fibers with the cut length of 1, 2 and 3 cm and with three levels of fiber volume percentage (FVP) by the hand molding method and were subjected to tensile and three-point bending tests. The results showed that fiber length, in the range of the research parameters, didn’t have a significant effect on the tensile and flexural properties. In general, adding date palm fibers (DPFs) didn’t improve tensile strength compared with the pure matrix, which may be due to week bonds between fibers and matrix and existence of structural defects in the samples. A fairly good agreement was observed between theoretical tensile moduli calculated using Tsai-Pagano model and experimental values. The results of bending test showed that adding 7.5 volume percent of DPFs leads to the improvement in flexural strength of the composites, however, in the higher FVP (10.7) it decreases which is due to the increase in fibers volume and thus less penetration of resin into them and deterioration of structural integrity of the samples. Moreover, by adding DPFs to epoxy the tensile modulus of the composite increased. This increase was observed in samples containing 7.5 and 10.7 FVP with a maximum value of 3.7 GPa in 7.5 FVP (105% enhancement).