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

Isolation and fractionation of cellulose nanocrystals from kenaf core

In this study, cellulose nanocrystals (CNC) were produced using acid hydrolysis method. Kenaf core was pretreated with 4 wt. % sodium hydroxide (NaOH), followed by bleaching using 1.7 wt. % sodium chlorite (NaClO2) in acetate buffer. The bleached fiber was acid hydrolyzed for 45 and 55 min using 64 wt. % sulfuric acid (H2SO4). The size distribution of the CNC segregated via differential centrifugation with different speed was also investigated. The CNC suspension obtained was centrifuged at 3000, 6000, 9000 and 12000 rpm. The resultant CNC suspension collected was characterized using Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD) and transmission electron microscopy (TEM). FTIR results showed the progressive removal of non-cellulosic constituents for each subsequent treatment. It also showed that the CNC produced after hydrolysing for 55 min has the highest degree of crystallinity (81.15%). CNC produced from acid hydrolysis process of 45 min have lengths between 50 and 270 nm while CNC produced from acid hydrolysis process of 55 min have length around 40 to 370 nm

Effect of stored oil palm trunk sap towards methyl ester synthesis / Nurnuha Shamsir... [et al.]

Oil palm trunk (OPT) has highest content of sap, 80% of the overall weight. OPT sap contains free sugars which can be converted into valuable compounds such as ester. The objective of this study is to determine the changes of free sugars at different storage time and the effect on methyl ester synthesis. The sap was extracted and stored at different durations time (1, 7, 14, 21 and 28 days). 10ml of dried sap was added with 100mg Fe2(SO4)3 EFB and 15ml of methanol. The mixture was put into the autoclave to be heated at 160 oC for 150 minutes. Free sugars found in OPT sap were glucose, fructose and sucrose. The free sugars vary upon the storage time and highest concentration of glucose and fructose achieved at day 21. This is due to hydrolysis of sucrose. The GC-MS analysis identified and quantified several methyl ester such as methyl pyruvate, methyl levulinate, methyl-9- oxononanoate and methyl palmitate. These findings confirmed that the free sugars from OPT sap were possible to be an alternative carbon in ester synthesi

As-spun bio-novolac fibre morphological study based on resin’s physico-chemical properties

Bio-novolac fibre made from phenol-formaldehyde derived oil palm empty fruit bunch (EFB) was produced using electrospinning method. The bio-novolac phenol-formaldehyde was prepared via liquefaction and resinification at two different molar ratios of formaldehyde to liquefied EFB (LEFB) (F:LEFB = 0.5:1 and 0.8:1). Electrospinning was applied to the bio-novolac phenol-formaldehyde (BPF) in order to form smooth and thin as-spun fibre. The BPF was electrospun at 15 kV and 15 cm distance between needle and collector at a flow rate of 0.5 mL/h. At lower molecular weight of BPF resin, beads formation was observed. The addition of poly(vinyl) butyral (Mw = 175,000 - 250,000) has improved the fibre formation with lesser beads hence produced more fibre. Polymer solution with higher molecular weight produced better quality fibre

Preparation and characterization of Fe3O4/regenerated cellulose membrane

In this study, magnetic cellulose membranes (MCM) have been prepared by using cotton linter as cellulose source and NaOH/urea as cellulose solvent at different magnetite content. Cellulose was dissolved in pre-cooled NaOH/urea solvent at -13°C to form cellulose solution. The cellulose solution then was mix with magnetite (Fe3O4) nanoparticles synthesized via co-precipitation method of Fe2+ and Fe3+ in the presence of sodium hydroxide (NaOH) to form MCM. The MCMs formed at different percentage of Fe3O4 i.e., 10, 20 and 30%. Analysis from vibrating sample magnetometer (VSM) shows that the saturation magnetization of the MCM increase as the percentages of Fe3O4 nanoparticles increased. However, the addition of Fe3O4 nanoparticles in the regenerated cellulose membrane has decreased the crystallinity index of MCM. The surface morphology of the MCM showed that the Fe3O4 nanoparticles were dispersed in the pore of the membrane. Tensile test showed decreasing in the tensile strength of the cellulose membrane with the addition of Fe3O4 nanoparticle

Membran selulosa kenaf terjana semula daripada larutan akues NaOH/urea yang digumpal menggunakan asid sulfurik

Membran selulosa terjana semula (MS) daripada pulpa teras kenaf telah berjaya dihasilkan menggunakan kaedah pra penyejukan dan digumpal menggunakan larutan asid sulfurik. MS disediakan daripada pelarutan selulosa kenaf dalam larutan akues NaOH/urea dan larutan selulosa seterusnya digumpal dengan H2SO4 pada kepekatan 5-12 peratus berat (% bt.) selama 1-10 min. Pengaruh kepekatan penggumpal H2SO4 dan masa penggumpalan ke atas struktur, saiz liang, sifat mekanik dan ketelusan cahaya MS telah dikaji menggunakan pembelauan sinar-X (XRD), imbasan mikroskop elektron tekanan boleh ubah (VPSEM), penguji regangan dan spektrofotometer ultra-violet sinar tampak (UV-vis). Keputusan VPSEM menunjukkan perubahan saiz liang membran bergantung kepada kepekatan larutan penggumpal H2SO4, manakala masa penggumpalan tidak mempengaruhi saiz liang membran. Membran yang direndam dengan larutan penggumpal pada kepekatan 10 % bt. dan masa pembekuan yang sederhana iaitu 5 min menunjukkan sifat mekanik yang lebih baik dengan nilai kekuatan regangan masing-masing 41.9 dan 43.5 MPa. Oleh itu, kajian ini dapat memberikan maklumat mengenai penyediaan MS dengan pelbagai saiz liang dan sifat mekanik dengan pengubahsuaian kepekatan dan masa penggumpalan

Proteomic analysis of stored core oil palm trunk (COPT) sap identifying proteins related to stress, disease resistance and differential gene/protein expression

Oil palm is the major crop grown and cultivated in various Asian countries such as Malaysia, Indonesia and Thailand. The core of oil palm trunk (COPT) consists of high sugar content, hence suitable for synthesis of fine chemicals and biofuels. Increase of sugar content was reported previously during prolonged COPT storage. However, until now, there has been no report on protein profiles during storage. Therefore, in this study, protein expression of the COPT during the storage period of one to six weeks was investigated using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) coupled with optical density quantification and multivariate analyses for measuring differentially expressed proteins. Accordingly, protein bands were subjected to tryptic digestion followed by tandem mass spectrometry (nanoLC-MS/MS) protein identification. The results from SDS-PAGE showed consistent protein bands appearing across the biological replicates ranging from 10.455 to 202.92 kDa molecular weight (MW) regions. The findings from the principal component analysis (PCA) plot illustrated the separation pattern of the proteins at weeks 4 and 5 of storage, which was influenced mainly by the molecular weights of 14.283, 25.543, 29.757, 30.549, 31.511, 34.585 and 84.395 kDa, respectively. The majority of these proteins are identified as those involved in stress- and defense-related, disease resistance, as well as gene/protein expression processes. Indeed, these proteins were mostly upregulated during the later storage period suggesting that long-term storage may influence the molecular regulation of COPT sap

Physico-mechanical properties of glass fibre reinforced biophenolic elastomer composite

In this study oil palm empty fruit bunches (EFB) fibres was used to synthesize biophenolic resin (BPR) at a different formaldehyde/liquefied empty fruit bunches (F/LEFB) molar ratio which is 1.0, 1.5 and 2.0. The higher molar ratio of F/LEFB used has resulted in an increased of viscosity and solid content of BPR resin. The first decomposition of BPR resin occured around 86 to 130°C due to the evaporation of low molecular weight substance which were water, free phenol and formaldehyde. Glass fibre reinforced biophenolic composite (BPC) and glass fibre reinforced biophenolic elastomer composite (BPEC) was successfully fabricated using BPR resin. The impact strength and flexural strain of BPEC were higher than that of BPC. The impact strength of BPEC 1.5 was the highest at 47.71 kJm-2. However, the flexural strength of BPEC was lower compared with BPC, which the highest flexural strength was obtained by BPC 1.0 at 65.18 MPa. The cross-sectional image from scanning electron microscope (SEM) of BPEC and BPC confirmed the presence of epoxidized natural rubber (ENR) improved the compatibility between glass fibre and BPR resin

Physico-mechanical properties of glass fibre reinforced biophenolic elastomer composite

In this study oil palm empty fruit bunches (EFB) fibres was used to synthesize biophenolic resin (BPR) at a different formaldehyde/liquefied empty fruit bunches (F/LEFB) molar ratio which is 1.0, 1.5 and 2.0. The higher molar ratio of F/LEFB used has resulted in an increased of viscosity and solid content of BPR resin. The first decomposition of BPR resin occured around 86 to 130°C due to the evaporation of low molecular weight substance which were water, free phenol and formaldehyde. Glass fibre reinforced biophenolic composite (BPC) and glass fibre reinforced biophenolic elastomer composite (BPEC) was successfully fabricated using BPR resin. The impact strength and flexural strain of BPEC were higher than that of BPC. The impact strength of BPEC 1.5 was the highest at 47.71 kJm-2. However, the flexural strength of BPEC was lower compared with BPC, which the highest flexural strength was obtained by BPC 1.0 at 65.18 MPa. The cross-sectional image from scanning electron microscope (SEM) of BPEC and BPC confirmed the presence of epoxidized natural rubber (ENR) improved the compatibility between glass fibre and BPR resin

Production of rigid polyurethane foams using polyol from liquefied oil palm biomass: Variation of isocyanate indexes

Development of polyurethane foam (PUF) containing bio-based components is a complex process that requires extensive studies. This work reports on the production of rigid PUFs from polyol obtained via liquefaction of oil palm empty fruit bunch (EFB) biomass with different isocyanate (NCO) indexes. The effect of the NCO index on the physical, chemical and compressive properties of the liquefied EFB-based PUF (EFBPUF) was evaluated. The EFBPUFs showed a unique set of properties at each NCO index. Foaming properties had affected the apparent density and cellular morphology of the EFBPUFs. Increasing NCO index had increased the crosslink density and dimensional stability of the EFBPUFs via formation of isocyanurates, which had also increased their thermal stability. Combination of both foaming properties and crosslink density of the EFBPUFs had influenced their respective compressive properties. The EFBPUF produced at the NCO index of 120 showed the optimum compressive strength and released the least toxic hydrogen cyanide (HCN) gas under thermal degradation. The normalized compressive strength of the EFBPUF at the NCO index of 120 is also comparable with the strength of the PUF produced using petrochemical polyol