Characterization of long lignocellulosic fibers extracted from Hyphaene thebaica L. leaves

The literature reveals there is a limited knowledge regarding the extraction of long natural fibers, in particular those extracted from leaves. This investigation aims to present the extraction process and the characterization of long natural cellulose fibers from doum palm leaves (Hyphaene thebaica L.), with properties suitable for polymeric composite materials and textile applications.

The resulting H. thebaica L. fibers were identified using Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The physical properties of the extracted fibers were measured to estimate the reliability of extraction conditions. Mechanical properties were evaluated to determine ultimate strength, Young’s modulus and strain-at-failure of the fibers of the doum leaves.

The following properties of the doum palm are listed in this paper: physical properties of doum palm fibers (H. thebaica L.), TGA, XRD of doum palm fibers, tensile properties of doum palm fibers and surface morphology of doum palm fibers.

Like synthetic fibers, the inclusion of short or long natural fibers into the polymer matrix can increase tensile, flexural and compressive strengths of these matrixes. Compared to the short-length natural fibers, longer-length fibers provide better reinforcements and therefore accord higher performances to the composites. Long fibers can also provide exceptional opportunities to develop a new class of advanced lightweight composites and have the potential to rival glass fiber in the manufacture of composite materials, using matrix materials, such as polypropylene, epoxy and phenolic resins.

The following values are presented in this paper: density of doum palm fibers = 1.14-1.40 g/cm², linear density (Tex) = 33.10 ±11.5, equivalent diameter (µm) = 178.72 ± 41.7, diameter (µm) = 137.02-220.42, tensile strength (MPa) = 124.84-448.10, Young’s modulus (GPa) = 8.06-19.59, strain-at-failure (%) = 0.81-2.86.