Comparative Thermal and Physical Investigation of Chemically Treated and Untreated Oil Palm EFB Fiber

Abstract

Natural fiber (NF) as a reinforcement is capable of playing a remarkable role in fiber reinforced polymeric composites (FRPC) owing to its low cost, low density, flexibility, CO2-neutrality, renewability, availability and eco-friendliness. In order to substitute for synthetic fiber, oil palm empty fruit bunch (EFB) fiber could be a potential candidate. This study aims to investigate the effect of chemical treatment on the morphological, thermal and structural properties of EFB fibers. Pulverized EFB fibers of 1-3 mm in length with a diameter of 100∼400 µm and density of 1.07 g/cm3 were used. Surface modification of fibers was carried out by conducting alkali treatment for three different soaking periods of 1, 13 and 24 hours, sodium bicarbonate treatment and alkali-silane treatment, and subsequently fibers were neutralized by rinsing with distilled water to the pH level of 7. The fibers were then dried at 70 °C for 24 hours in an oven. To examine the physical and thermal properties of the fibers, Scanning Electron Microscope (SEM), Energy-Dispersive X-ray (EDX) spectroscopy, Fourier Transformed Infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA) tests were conducted. SEM was employed to investigate the morphology of fibers. The rougher and cleaner surface of treated EFB fibers were observed relative to those of untreated ones. EDX analysis showed the amount of carbon and oxygen in the fibers. FTIR revealed chemical structure of fibers. TGA tests were performed and showed greater thermal degradation temperature of alkali and alkali-silane treated fibers compared to those of sodium bicarbonate and untreated fibers for the entire temperature increment from 30 °C to 600 °C.