Comparison between the Chemical-physical Characteristics of Kenaf Bast and Stem Nanofibers

In the present study, chemical-physical properties of nanofibers isolated from whole kenaf stem and kenaf bast fibers were characterized by Transmission Electron Microscope (TEM), Fourier Transform Infrared (FTIR), Thermogravimetric Analysis (TGA), and X-ray Diffraction (XRD) analysis. The isolation was done using chemo-mechanical processing where the chemical methods were based on NaOH-AQ (anthraquinone) and three-stage bleaching (DEpD) processes. The mechanical techniques involved refining, cryo-crushing and high-pressure homogenization. Microscopy study showed that the diameter range of isolated nanofibers from kenaf stem was finer than kenaf bast nanofibers, while their length was similar and in the micrometer range. Fourier transform infrared spectroscopy (FTIR) study demonstrated that the functional groups for both nanofibers were almost the same and no significant differences were observed. The results from thermo-gravimetric analysis showed a better thermal stability for kenaf bast nanofibers compared to the kenaf stem nanofibers. X-ray analysis revealed that the crystallinity of the studied nanofibers was increased after the chemo mechanical isolation process. In addition, the crystallinity was 81% and 63% for kenaf bast and kenaf stem nanofibers, respectively.