Alkali lignin depolymerization under eco-friendly and cost-effective NaOH/urea aqueous solution for fast curing bio-based phenolic resin

Li, Jiongjiong; Zhang, Jizhi; Zhang, Shifeng; Gao, Qiang; Zhang, Wei

doi:10.1016/j.indcrop.2018.04.027

Cited by 70 publications

(42 citation statements)

References 42 publications

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“…(LCC) bond effectively without leaving the CH 2 linkage on the lignin structure. The β-O-4 structures in the lignin are shown between 5.9-6.6 ppm and the active proton at C5 position was also observed at signal around 6.96 ppm (Li et al, 2018;Hussin et al, 2013;Rashid et al, 2018). The presence of signals between 6.0 and 8.9 ppm indicates the presence of aromatic protons in the lignin's unit (Rashid, et al, 2018).…”

Section: Ft-ir Spectra For Microwave-assisted Acetosolv Lignin In Thementioning

confidence: 93%

“…The sharp peak shown at the range of 2.33-2.51 ppm is the solvent used; DMSO-d6 to solubilise lignin for the sample preparation phase. The presence of aliphatic moiety is shown at the signals between 0.8 and 1.5 ppm (Li et al, 2018). The methoxyl proton can be observed by the presence of a signal between 3.1 and 4.0 ppm.…”

Section: Determination Of Chemical Structural Using Ft-irmentioning

confidence: 94%

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Effect of Catalysts on the Yield and Properties of Lignin From Microwaveassisted Acetosolv Extraction of Oil Palm Empty Fruit Bunch Fibres

Nor¹,

Rasidi²,

Salim³

et al. 2020

JOPR

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Acetosolv is an enhancement organosolv technique utilising acetic acid as solvent and produces high purity of lignin. However, the limitation of this technique in the conventional heating method is the high energy consumption during a long reaction time. Therefore, the employment of microwave is used to overcome this limitation with the expectation of a lower power consumption and short reaction time. In this study, three types of catalysts, sulphuric acid (H 2 SO 4) , aluminium choride (AlCl 3), and chromium nitrate [Cr(NO 3) 3 ] were used to investigate the lignin extraction performance and its properties from microwave-assisted acetosolv (MWA) treatment of oil palm empty fruit bunches (EFB). The highest yields of lignin (76.98%) were obtained using an aqueous solution of acetic acid combined with 3.0% of H 2 SO 4 under 110°C for 30 min. Meanwhile, AlCl 3 performed almost similar to H 2 SO 4 , providing lignin yield of 71.57% at the highest temperature of 110°C. The usage of microwave-assisted technique also produces a high yield and high purity of lignin. It is also proven that AlCl 3 can be a substitute to Bronsted acid for lignin extraction. However, Cr(NO 3) 3 was found not suitable for the lignin's extraction despite having a high potential for cellulose extraction.

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Section: Ft-ir Spectra For Microwave-assisted Acetosolv Lignin In Thementioning

confidence: 93%

Section: Determination Of Chemical Structural Using Ft-irmentioning

confidence: 94%

Effect of Catalysts on the Yield and Properties of Lignin From Microwaveassisted Acetosolv Extraction of Oil Palm Empty Fruit Bunch Fibres

Nor¹,

Rasidi²,

Salim³

et al. 2020

JOPR

View full text Add to dashboard Cite

show abstract

“…The reactivity of lignin can be increased by chemical and thermal modification techniques such as demethylation, methylolation, and phenolation [6]. Additionally, alkaline depolymerization of lignin has been tested with NaOH/ Urea solutions, yielding a product with increased phenolic hydroxyls [7]. Metal-catalyzed (heterogeneous) oxidative solvolysis of lignin was studied by Ouyang et al [8] using H 2 O 2 as oxidant, where they achieved an 18% yield of monophenols when using methanol and water as co-solvents.…”

Section: Introductionmentioning

confidence: 99%

Effect of Process Variables on the Solvolysis Depolymerization of Pine Kraft Lignin

Goldmann

Anthonykutty

Ahola

et al. 2019

Waste Biomass Valor

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Lignin modification opens the possibility of using it in polyol bio-based polymers, such as phenol-formaldehyde resins, polyurethanes, composites, and binders. Pine kraft lignin Indulin AT was partially depolymerized and the resulting products analyzed to determine their degree of valorization. Depolymerized lignin products were analyzed by GPC-SEC (molar mass), ∆ε-IDUS (phenolic hydroxyls), HACL (formaldehyde uptake), 13 C-NMR (hydroxyl and methoxyl groups), and 1 H-DOSY (molar mass distribution). The dominant parameter in lignin depolymerization by solvolysis was reaction temperature. According to the results, a higher reaction temperature decreases the average molar masses and PDI of lignin as well as the primary and secondary aliphatic hydroxyls, while simultaneously increasing the phenolic hydroxyls and formaldehyde uptake of lignin. Other variables (time, formic acid wt %, ethanol wt %, lignin load) had lesser effects. Partial depolymerization by solvolysis in mild conditions without catalyst is a viable valorization route for lignin, by which lignin properties can be significantly improved.

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“…hydrolyzed by hydroxide ions from a strong nucleophile source such as sodium hydroxide [51] as shown in Eq. 12.…”

Section: Non-wood Use and Their Limitationsmentioning

confidence: 99%

“…Acetyl groups naturally present in sugarcane bagasse provides an active point in a molecule that is crucial for chemical properties of that specific molecule. Acetyl groups are easily hydrolyzed by hydroxide ions from a strong nucleophile source such as sodium hydroxide [ 51 ] as shown in Eq. (12) .…”

Section: Introductionmentioning

confidence: 99%

Crop residues used as lignocellulose materials for particleboards formulation

Kariuki

Wachira

Kawira

et al. 2020

Heliyon

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Efforts to reduce pressure on use of wood in particleboard formulation have included the use of non-wood materials such as crop residues. Physical and mechanical properties are determined by the number of the hydroxyl (-OH) groups. Hydroxyl (-OH) groups attracts water molecules through hydrogen bonding affecting water absorption (WA) and thickness swelling (TS). WA and TS affect curing process of adhesive. Curing process of adhesives affects the mechanical characteristics of formulated particleboards. These challenges have been acted upon continuously through research. This review paper presents crop residues used as alternative lignocellulose material source in particleboard formulation and the various advances that have been made to improve on the properties of the resultant particleboards. Improvement over time of the non-wood material in composite materials focusses on increasing water resistance and compatibility between lignocellulose and binder. Crop residues-based are used in making medium and low density particleboards. These boards have shown good mechanical characteristics which include modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding (IB). MOR, MOE and IB have over time been improved by enhancing chemical compatibility of lignocellulose material and the binders. Water absorption and thickness swelling remain challenge. This review paper further explored various methods of improving water absorption and thickness swelling of crop-residue based particleboards.

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Alkali lignin depolymerization under eco-friendly and cost-effective NaOH/urea aqueous solution for fast curing bio-based phenolic resin

Cited by 70 publications

References 42 publications

Effect of Catalysts on the Yield and Properties of Lignin From Microwaveassisted Acetosolv Extraction of Oil Palm Empty Fruit Bunch Fibres

Effect of Catalysts on the Yield and Properties of Lignin From Microwaveassisted Acetosolv Extraction of Oil Palm Empty Fruit Bunch Fibres

Effect of Process Variables on the Solvolysis Depolymerization of Pine Kraft Lignin

Crop residues used as lignocellulose materials for particleboards formulation

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