Extraction and characterization of natural cellulosic fiber from the bark of the Wikstroemia monnula plant as potential reinforcement in composites

The aim of this paper is to study the possibility of using of Wikstroemia monnula (W. monnula) fibers as reinforcement in composites. The fibers are extracted from the stem bark of W. monnula plant, which are notable for their strength and length. To use these cellulosic fibers as reinforcement in composites, it is necessary to investigate their intrinsic properties. Through multi-scale characterization, the fibers demonstrate exceptional structural and functional properties. The low density (1.32 g·cm^-3) combined with the fiber porosity of 49.22 %, provides lightweight advantages while reducing energy consumption during composite processing. The high cellulose content (46.25 %) and crystallinity index (63.22 %) work synergistically to enhance mechanical strength. The fibers demonstrate superior thermal stability, with a maximum degradation temperature of 345 °C and a kinetic activation energy of 94.64 kJ·mol^-1, ensuring thermal resistance during processing. The fiber bundles achieve a tensile strength of 305.31 MPa and a Young's modulus of 15.76 GPa, surpassing that of conventional plant fibers. The fibers are hydrophobic, with a contact angle of 133.4°, which minimizes the risk of moisture absorption. The smooth fracture morphology eliminates sharp edges, addressing safety concerns. These findings indicate that W. monnula fiber is a potential reinforcement for composites.