Microwave assisted liquefaction of wheat straw alkali lignin for the production of monophenolic compounds

Water-soluble carboxymethylated lignin (CML) was synthesized using wheat straw alkali lignin (WAL) in aqueous medium. The process of carboxymethylation was optimized with respect to the NaOH concentration, monochloroacetic acid concentration, reaction temperature and time. The optimized product has a yield of 80.47% and a carboxyl group content of 2.8231 mmol•g-1, respectively. The optimum conditions for carboxymethylation are NaOH concentration of 20.0% (wt%), monochloroacetic acid concentration of 37.5% (wt%), temperature of 70 °C and time of 90 min. The optimized CML was characterized by FTIR spectroscopy, 1H NMR spectroscopy and interfacial tension apparatus. The result shows that the substitution reaction of carboxymethylation occurs simultaneously in the phenolic hydroxyl group and aliphatic hydroxyl group in WAL. CML has the surface activity in water for industrial application as dispersant.

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Effects of Pretreatment Methods of Wheat Straw on Adsorption of Cd(II) from Waterlogged Paddy Soil

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16020205 ◽

2019 ◽

Vol 16 (2) ◽

pp. 205 ◽

Cited By ~ 16

Author(s):

Mengjie Wu ◽

Hongyu Liu ◽

Chunping Yang

Keyword(s):

Wheat Straw ◽

Paddy Soil ◽

Morphological Changes ◽

Ethanol Solution ◽

Acid Oxidation ◽

Organic Carbon Content ◽

Microwave Assisted ◽

Dynamic Variations ◽

Behavior Study ◽

Effective Removal

Two types of pretreatment categories, namely microwave-assisted alkalization and microwave-assisted acid oxidation, were used to synthesize novel wheat straw adsorbents for the effective removal of Cd(II) in simulated waterlogged paddy soil. A systematic adsorption behavior study, including adsorption kinetics and adsorption isotherms was conducted. Results showed that wheat straw pretreated by microwave-assisted soaking of NaOH and ethanol solution obtained the highest Cd(II) removal efficiency of 96.4% at a reaction temperature of 25 ℃, pH of 7.0, initial Cd(II) concentration of 50 mg/L, and adsorbent/adsorbate ratio of 10 g/L. Sequential extraction experiment was carried out to analyze the changes of different of Cd(II) in soil, the aim of which was to study the mobility of Cd(II) and then evaluate the toxicity that Cd(II) might bring to plants. A 60-day incubation was performed to investigate the dynamic variations of soil pH and dissolved organic carbon content over incubation time. Characterization analyses revealed the morphological changes of wheat straw adsorbents, which suggested that those pretreatment methods were of significance. This study provided an environmentally friendly way to reuse agricultural wastes and remedy Cd(II) contaminated soil.

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Zinc-based deep eutectic solvent-mediated hydroxylation and demethoxylation of lignin for the production of wood adhesive

RSC Advances ◽

10.1039/c6ra18290a ◽

2016 ◽

Vol 6 (92) ◽

pp. 89599-89608 ◽

Cited By ~ 26

Author(s):

Shu Hong ◽

Hailan Lian ◽

Xiang Sun ◽

Dong Pan ◽

Arturo Carranza ◽

...

Keyword(s):

Wheat Straw ◽

Chemical Reactivity ◽

Choline Chloride ◽

Deep Eutectic Solvent ◽

Wood Adhesive ◽

Alkali Lignin ◽

Different Temperatures

Choline chloride–ZnCl2 deep-eutectic solvent (ChCl–ZnCl2 DES), mole ratio 1 : 2, was used to improve the chemical reactivity of wheat straw alkali lignin under different temperatures and times of pretreatment.

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The Property of Waterborne UV-Curable Polyurethane Based on Alkali Lignin of Wheat Straw

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.834-836.199 ◽

2013 ◽

Vol 834-836 ◽

pp. 199-202 ◽

Cited By ~ 1

Author(s):

Ji Lei Chao ◽

Fu Qiang Chu ◽

Chang Li Xu ◽

Hui Wang ◽

Yu Xin Liu

Keyword(s):

Mechanical Properties ◽

Optical Properties ◽

Wheat Straw ◽

Loss Factor ◽

Loss Modulus ◽

Added Value ◽

Light Transmittance ◽

Optical Performance ◽

Uv Curable ◽

Alkali Lignin

To improve the added value of lignin, the modified alkali lignin of wheat straw was used to prepare waterborne UV-curable polyurethane. The purpose of this paper is to discuss the properties of the cured films made from the above lignin-based polyurethane. The mechanical and optical properties of the cured films were investigated. Results showed that the tensile storage modulus, tensile loss modulus, and tensile loss factor of the cured film were influenced by the addition of the lignin, which indicated that proper dosage of the lignin could change the micro-phase separation structure and improve the mechanical properties of the product. The addition of the lignin also influenced the gloss and light transmittance of the cured film. On the whole, the lignin-based polyurethane exhibits good mechanical and optical performance if proper proportion of the lignin was added to the product. The study was beneficial for utilizing the lignin in high value products.

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