The effects of alkaline treatment on the oil residue, thermal properties and surface morphology of oil palm Mesocarp fiber

Abstract

Oil palm mesocarp fiber (MF) holds the potential to be used as a filler in polymeric biocomposite systems. To further improve the dispersion and interfacial adhesion between the fiber and polymer matrix, MF was treated with sodium hydroxide (NaOH) at different concentrations (1%, 3%, 5%, 8% and 10%) and soaking times. (1 h, 4 h, 8 h, 24 h and 48 h). The effects of NaOH solution and soaking duration on the oil residue, thermal stability and surface morphology of the MF were investigated. It was found that the soaking time had a prominent effect on the oil residue content compared to the NaOH concentration. Fourier transform infrared spectra demonstrated that alkaline treatment decreased the peak intensities of the carboxyl group and alkene of the fatty acid (oil) at 1630–1700 cm–1. Meanwhile, the clean and smooth surface of MF was revealed by scanning electron microscopy, indicating the removal of noncellulosic components. The treatment also reduced the degree of crystallinity of MF, as reflected by its melting temperature (Tm) and heat of melting (?Hm), as measured by using differential scanning calorimetry. MF with oil residue is envisioned to improve the fiber dispersion across the polymer matrix during polymer processing.