Unveiling the potential of cellulose-rich Livistona jenkinsiana leaf stalk fiber: A - lignocellulosic reinforcement for sustainable polymer composite applications

Growing environmental concerns and the increasing demand for sustainable materials have encouraged the exploration of new cellulose-rich plant-based fibers as alternatives to synthetic reinforcements in polymer composites. In this study, Livistona jenkinsiana leaf stalk fiber (LJLSF), an abundantly available but previously unexplored natural resource, was extracted and comprehensively characterized to evaluate its potential for bio-composite applications. The extracted fibers exhibited a density of 1330 ± 60 kg/m3 and contained 57.9 ± 1.2% cellulose, indicating a cellulose-rich lignocellulosic structure. Contact angle analysis showed a decrease from 76.9 ± 2.7° to 54.1 ± 5.1° within 20 s, confirming LJLSF's hydrophilic nature and good wettability. FTIR and NMR analyses confirmed the characteristic functional groups and molecular structure of cellulose, hemicellulose, and lignin. XRD analysis revealed a highly ordered cellulose structure with a crystallinity index of 78.04% and a crystallite size of 2.20 nm. Thermal analysis showed that LJLSF remained stable up to 241.20 °C, with a maximum degradation temperature of 310.18 °C and an activation energy of 75.21 kJ/mol, indicating its suitability for processing with polymer matrices below this temperature. SEM and AFM observations revealed a rough surface morphology, with an average roughness of 19.43 nm, which could support mechanical interlocking with polymer matrices. The fiber exhibited a tensile strength of 102.04 ± 15.74 MPa and a tensile modulus of 16.70 ± 4.22 GPa. Overall, the high crystallinity, adequate thermal stability, rough surface morphology, and favourable mechanical performance demonstrate that LJLSF can serve as a promising sustainable reinforcement for lightweight polymer composite applications.