Journal of Oil Palm Research Vol. 24 (2) August 2012, p. 1412-1420 ROSNAH Mat Soom* ; ASTIMAR Abdul Aziz* ; WAN HASAMUDIN Wan Hassan* ; AB GAPOR Md Top*
Cellulose, in combination with lignin and hemicellulose, is found in all plant materials. It is also the most abundant form of plant biomass. In the oil palm industry, empty fruit bunches (EFB), which are generated in large amounts at the palm oil mill, is made up of approximately 37% α-cellulose (on a dry weight basis). The use of this oil palm by-product may be expanded by the chemical modification of the cellulose into products of high value, such as cellulose ether. This study attempted to synthesise water-soluble cellulose ether, particularly sodium carboxymethylcellulose (NaCMC), from the EFB fibre. The properties of EFB-based NaCMC including the degree of substitution (DS), and viscosity were studied. In addition, the a-cellulose and NaCMC were analysed for their structural properties by Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffractometry. The properties of EFB-based NaCMC in comparison to the United States Pharmacopeia (USP) grade NaCMC (from Sigma-Aldrich) were discussed. EFB-based NaCMC exhibited viscosity of about 400 cps (2% at 25°C) while USP grade NaCMC exhibited viscosity of 500 cps (2% at 25°C), i.e. slightly higher than EFB-based NaCMC. The infrared spectrum of a-cellulose from EFB was identical to that of commercial cellulose (from Sigma-Aldrich) with the presence of C-O-C, C-C, O-H and C-H bands. The typical absorption bands observed between 1300 cm-1 and 1580 cm-1 on the infrared spectra for both the EFB-based NaCMC and USP grade NaCMC indicated the presence of the COO group. As for the X-ray diffractogram, the profiles of both the EFB-based NaCMC and USP grade NaCMC were identical, even though the EFB-based NaCMC was less amorphous in structure compared with that the USP grade NaCMC. The results suggest chemical disruption of the cellulose crystallinity by breaking hydrogen bonds in cellulose and opening the structure to accessibility by other chemicals. These findings on NaCMC from an underutilised by-product of the palm oil industry could contribute towards the development of an oil palm-based specialty chemicals industry.KEYWORDS:
* Malaysian Palm Oil Board,
P. O. Box 10620, 50720 Kuala Lumpur, Malaysia.