Effect of alkali treatment on novel natural fiber extracted from the stem of Lankaran acacia for polymer composite applications

In the present scenario, the search for novel plant fibers able to be used as reinforcement of polymer composites is highly appreciable. In this work, Lankaran acacia fibers are extracted from its stem by a manual retting process. Lankaran acacia fiber polymer composites (LAPC) were fabricated with various weight percentages of Lankaran acacia fibers (5, 10, 15, 20, and 25 wt.%) using a hand layup process. The specimens were prepared using both untreated and alkali-treated Lankaran acacia fibers (LAFs). Tensile, flexural, and impact strength were evaluated. In this research, maximum tensile, flexural, and impact strength of 46.22 MPa, 60.31 MPa, and 95.21 J/m respectively obtained for LAPC loaded with 20 wt.% treated lankaran acacia fiber. Alkali treatment helped to enhance the bonding between the LAPC and epoxy matrix, which resulted in higher mechanical properties in the fabricated LAPC. Tensile strength obtained in LAPC loaded with 20 wt.% LAF improved the tensile strength up to 8.52%, flexural strength up to 15.50%, and impact strength up to 42.6%. From the scanning electron microscope (SEM) analysis, it was observed that alkali treatment helped to fill the small cracks, holes, and pores presented in the natural fiber composites, which in turn improved the tensile, flexural, and impact strength of the composites.