Sustainable lignocellulosic fiber from Tephrosia purpurea stem: Physicochemical characterization toward green polymer composite reinforcement

The present investigation concentrates on the characterization of new raw natural fibers obtained from Tephrosia purpurea plant. The thermal stability of the Tephrosia purpurea stem layer fiber (TP SF ) was tested by means of thermogravimetric analysis (TGA). Morphological study was performed on the TP SF ’s surface via scanning electron microscopy (SEM), and the roughness measurements on the fiber surface were taken with the help of atomic force microscopy (AFM) analysis. The results of the chemical composition analyses disclosed that the presently investigated untreated fiber contains 63.87 ± 6.28 wt% cellulose, 14.26 ± 6.24 wt% hemicellulose and 12.82 ± 3.57 wt% lignin contents. The crystallinity index (CI) and crystallite size of the TP SF was confirmed to be 86.59% and 4.48 nm respectively, ensuring an excellent structural order. TGA results explored that the TP SF has thermal stability up to 225 °C, which confirmed its suitability for moderate thermal resistance applications. The low density (844 ± 26.47 kg/m³) and high crystallinity further support its potential as a lightweight reinforcement material. The explored characteristics of TP SF indicate its potential for polymer composite applications; however, further composite fabrication and mechanical validation studies are required to fully establish its reinforcement capability.