Effect of alkaline treatment on mechanical properties of composites between vetiver fibers and epoxy resin

Abstract

Abstract In this research, we were interested in studying whether vetiver fibers (VFs) treated with different concentrations of sodium hydroxide (NaOH) affect the mechanical properties of VF and epoxy resin (ER) composite material in a better way. As part of the experiment, VFs were treated with NaOH in various concentrations ranging from 0.5, 1, 1.5, 2, 2.5, and 3 mol/L. All of them were molded into composite material in the ratio of 10 wt% with ER. After that, they were tested for mechanical properties such as the tensile strength, impact strength, bending strength, and compressive strength to find the best mechanical properties. In addition, the surface was investigated with scanning electron microscopy (SEM) for adhesion of the VFs with ER. The results of the experiment were not as expected. We found that, increasing the concentration of vetiver treated with sodium hydroxide resulted in a decrease in the mechanical properties of the composite. The best values for impact, tensile, bending, and compressive strengths were 256.42 kJ/m2, 38.45 MPa, 43.70 MPa, and 110.27 MPa, respectively, and 0.5 mol/L is the best concentration of NaOH for mechanical strengths of the composites. Moreover, from SEM technique, it was found that the mechanical properties decreased at higher concentrations. This may be caused by damage to the VFs due to excessive NaOH corrosion and this point should be taken for further study.