Physico-chemical characterization of Sambucus ebulus L. plant stem fiber

This study aims to obtain a sustainable substitute for man-made fibers using Sambucus ebulus L. as a reinforcement in the polymer composites. With this purpose, an extensive characterization of Sambucus ebulus L. stem fiber was performed. The chemical composition was obtained approximately as 76 wt.% cellulose, 66 wt.% hemicellulose, and 4.47 wt.% lignin. Scanning electron microscope analysis proved that the fibers are nonuniform and have rough surface along the length. The elemental composition was found as 58.67% carbon and 40.34% oxygen with energy-dispersive X-ray analysis. Furthermore, the fiber diameter was estimated as 759.41 mu m with image processing from scanning electron microscope graphs of fibers. X-ray diffraction analysis verified the existence of crystalline cellulose having 72% crystalline index with 3.9 nm crystalline size. Functional groups of the fiber were determined with Fourier transform infrared analysis. A single fiber tensile test found out that the fibers have the mean tensile strength, elongation at break, and Young's modulus of 90.6 MPa, 6.45%, and 1.46 GPa, respectively. Moreover, the obtained fibers are thermally durable to 456.98 degrees C with thermogravimetric analysis. The results indicate that Sambucus ebulus L. stem fibers have the comparable properties to other natural cellulosic fibers. It is suggested to use Sambucus ebulus L. stem fiber in composites as reinforcement to substitute for man-made fibers.