Chemical and thermal properties of purified kenaf core and oil palm empty fruit bunch lignin

Chemical and thermal properties of pure lignin are depending on the plant origin, extraction method and type of lignocellulosic. In this study, lignin from oil palm empty fruit bunch (EFB) and kenaf core were recovered from soda black liquor by two steps of acid precipitation with hydrochloric acid and followed by soxhlet with n-hexane. The XRD analysis of purified EFB lignin (EAL) and purified kenaf core lignin (KAL) exhibited amorphous properties, similar to the standard alkali lignin (SAL). The FTIR and Raman spectra showed that all samples consist of HGS unit. In FTIR, the syringyl unit is assigned at (1125 cm-1), (1327 and 1121 cm-1) and (1326 and 1117 cm-1) meanwhile the guaicyl unit is assigned at (1263, 1212 and 1028 cm-1), (1271, 1217 and 1028 cm-1) and (1270, 1211 and 1030 cm-1) for SAL, EAL and KAL, respectively. The peak around 1160 cm-1 represents C-O stretching of conjugated ester group present in HGS lignin. As for Raman, the HGS unit exists in the range of 1100-1400 cm-1. Among the purified samples, the TGA result showed that KAL has a better thermal stability with the residue of 36.49% and higher Tg value which is 152.69°C

Effect of Impregnated Phenolic Resins on the Cellulose Membrane for Polymeric Insulator

In this study, a cellulose membrane (CM) was chemically treated with phenolic (PF) resin to improve its performance as a polymeric insulator. The CM was prepared from kenaf pulp, and the PF was synthesized from oil palm empty fruit (EFB) fibre. Four different concentrations of synthesized PF resin (5, 10, 15, and 20 wt.%) were impregnated under wet or dry conditions. Thermal analysis of the phenolic cellulose membrane (PCM) showed that the samples had good chemical interaction and compatibility. The PF uptake in the wet phenolic cellulose membrane (PCMW) was higher than in the dry phenolic cellulose membrane (PCMD). During the PF uptake, the CM underwent solvent exchange and absorption in wet and dry membranes, respectively. This difference also affected the crosslinking of PCM samples via the formation of methylene bridges. Due to the PF treatment, the PCM showed lower water absorption than CM. The PF concentrations also affect the surface roughness and electrical properties of PCM samples. These findings prove that PCM can be used as a renewable and green polymer electrical insulator

Factors affecting cellulose dissolution of oil palm empty fruit bunch and kenaf pulp in NaOH/urea solvent

The factors responsible for the low solubility percentage of oil palm empty fruit bunch (OPEFB) cellulose pulp compared to kenaf when dissolved in aqueous NaOH/urea solvent system was reported. Physical and chemical properties of both cellulose pulp were studied and compared in terms of the lignin content, viscosity average molecular weight (Mη), crystallinity index (CrI), cellulose pulp structure and their zero span tensile strength. The structure of both OPEFB and kenaf cellulose pulp were characterized using high powered microscope and field emission scanning electron microscopy (FESEM) assisted by ImageJ® software. The results show that the most significant factor that affected the OPEFB and kenaf cellulose dissolution in NaOH/-urea solvent was the Mη with OPEFB having a higher Mη of 1.68×105 compared to 5.53 × 104 for kenaf. Overall, kenaf cellulose appeared to be produced in higher quantities presumably due to its lower molecular weight with superior tensile strength and permeability in comparison to OPEFB