Synthesis and Characterization of Carboxymethyl Cellulose Derived from Empty Fruit Bunch

Abstract

Oil palm empty fruit bunch (EFB), a cellulose rich lignocellulosic biomass has huge potential to be utilised as a raw material for the synthesis of carboxymethyl cellulose (CMC). In this study, CMC was synthesised from EFB extracted cellulose at the optimum carboxymethylation reaction conditions. The extracted cellulose yield obtained by alkaline treatment followed by bleaching with hydrogen peroxide was 45.5 wt.%. The cellulose structure was elucidated using thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) patterns. Meanwhile, the synthesised CMC was characterised with FT-IR, XRD and scanning electron microscopy (SEM). The maximum degree of substitution (DS) obtained was 1.30 with the yield of 177.51 wt.% and purity 89% determined using chemical methods at the optimum conditions of 30 wt.% of NaOH, 18 g of SMCA, 65 °C, 3 h reaction time and less than 75 μm of EFB-cellulose particle size. XRD analysis inferred low crystallinity while FTIR spectra verified the CMC structure and presence of different functional groups. The results for DS and EFB CMC yield obtained from this work were considerably higher than those reported in the literature. The synthesised EFB CMC can be further utilised in various industries such as detergent, mining, flotation, and oil and gas drilling muds applications.

Micro-/Nano-Carboxymethyl Cellulose as a Promising Biopolymer with Prospects in the Agriculture Sector: A Review

“…FTIR, XRD, SEM [61] Terry towel waste An amount of 40% NaOH, isopropyl alcohol (alkalization reaction, 90 min); monochloroacetic acid was added to the mixture for 30 min (then kept at 55 • C for 3.5 h). Methanol (70%, v/v) was added to the reactor, and the mixture was neutralized with acetic acid (90% v/v).…”

“…The degree of substitution (DS) of CMC (Equation (1)) means the average number of hydroxyl groups of cellulose substituted with carboxymethyl and sodium carboxymethyl groups [ 59 ]. The yield of CMC was calculated using Equation (2) [ 59 , 60 , 61 ]. …”

“…The solution was mixed with pure acetone (50 mL) to recover the CMC. The CMC obtained was filtered, dried at 70 °C, and its purity determined using Equation (3) [ 59 , 60 , 61 ]. …”

“…Several parameters related to CMC should be checked to characterize CMC; these include: (1) morphology analysis by scanning electron microscopy (SEM), (2) confirmation of the presence of functional groups with FT-IR, (3) recording of XRD patterns of the products by X-ray diffractometry, and (4) determination of solubility and pH of CMC by adding 5 g of powder to 50 mL of double distilled water [ 59 , 60 , 61 ]. In one study, 15 g of oil palm frond cellulose powder was alkalized (at 30 °C for 60 min in a water bath shaker) with 50 mL of 37.9%, 40%, 45%, 50%, or 52.1% NaOH in 450 mL isopropanol.…”

“…The solution was mixed with pure acetone (50 mL) to recover the CMC. The CMC obtained was filtered, dried at 70 °C, and its purity determined using Equation (3) [59][60][61]. In other research, cellulose was first extracted from asparagus stalks and stored in a polyethylene glycol bag.…”