Characterization of Control and Chemically Modified Kenaf Fiber

Natural fibers are very flexible materials; their properties vary with physical structure and chemical composition. Chemical treatment of fiber can chemically modify, clean the fiber surface, increase the surface roughness and stop the moisture absorption process. In the present study, kenaf bast fibers were treated with sodium hydroxide (NaOH), sodium carbonate (Na2CO3), ortho phosphoric acid (H3PO4), acetic acid (CH3COOH) and zinc chloride (ZnCl2) each with different concentrations. The morphological properties were investigated using scanning electron microscopy (SEM) which shows many impurities on untreated kenaf fiber surface. NaOH and ZnCl2 treated kenaf fiber surface is more rough than other chemical treatments. X-ray diffraction (XRD) was carried out to evaluate crystallinity index. NaOH treated kenaf fiber shows highest crystallinity index of 76.87%. Fourier transform infrared (FTIR) spectroscopy was performed to characterize chemical functional groups. In untreated kenaf fiber broad band at 3469 cm(-1) confirms the presence of OH group. After chemical treatments this band disappears which confirms the removal of the OH groups. Thermo gravimetric analysis (TGA) carried out shows low fixed carbon content (64%) and maximum ash content (22%) for NaOH treated kenaf fiber.