scholarly journals Preparation of a Low Reducing Effect Sulfonated Alkali Lignin and Application as Dye Dispersant

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 982 ◽  
Author(s):  
Yanlin Qin ◽  
Xuliang Lin ◽  
Yaoqin Lu ◽  
Siyuan Wu ◽  
Dongjie Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Temperatures ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Groups ◽  
Sodium Lignosulfonate ◽  
Sulfonic Group ◽  
Alkali Lignin ◽  
Group Content ◽  
Phenolic Hydroxyl Groups ◽  
Condensed Lignin

A novel grafting hydroxypropyl sulfonated and blocking condensed lignin (GSBAL) dye dispersant was prepared based on alkali lignin (AL) by sulfonation and etherification reactions. The significant increase in the sulfonic group content and the molecular weight endow GSBAL with excellent dispersity and stability at high temperatures. More importantly, the unfavorable property of the reducing effect of AL was largely reduced since over 80% of the phenolic hydroxyl groups were blocked. The functional azo groups in the dye could be mostly retained. The reducing rate of dye with GSBAL was decreased to 6.54% (25 °C), much lower than 18.62% for sulfomethylated alkali lignin (SAL) and 15.73% for sodium lignosulfonate (NaLS). The dispersity and exhaustion of the dye bath with GSBAL dispersant was significantly improved compared with that of a dye bath with SAL and NaLS.

The Influence of Laccase Modification on the Adsorption of Lignosulfonate

2012 ◽  
Vol 550-553 ◽  
pp. 1266-1269
Author(s):  
Hai Feng Zhou ◽  
Dong Jie Yang ◽  
Meng Xian Bai ◽  
Xue Qing Qiu
Keyword(s):  
Self Assembly ◽  
Gel Permeation Chromatography ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Groups ◽  
Mean Square ◽  
Sodium Lignosulfonate ◽  
Gel Permeation ◽  
Initial Decrease ◽  
Assembly Technology ◽  
Phenolic Hydroxyl Groups

The ability of commercial laccase to improve the adsorption of sodium lignosulfonate (SL) without any mediator was studied. When SL are modified by laccase, gel permeation chromatography (GPC) shows an initial decrease followed by an extensive increase in molecular weight (Mw). Furthermore, the decrease in Mw is accompanied by an increase in phenolic hydroxyl groups, while the increase in Mw is accompanied by the decrease in phenolic hydroxyl groups. The laccase modification does not affect the content of the sulfonic group. Furthermore, the electrostatic self-assembly technology indicates that the adsorbed amount and the root-mean-square (RMS) of SL/PDAC multilayers increase obviously with the increase of the incubation time, which might be due to the influence of the Mw and the adsorption configuration.

Fractionation of lignosulfonates: comparison of ultrafiltration and ethanol solubility to obtain a set of fractions with distinct properties

Holzforschung ◽  
2015 ◽  
Vol 69 (2) ◽  
pp. 127-134 ◽  
Author(s):  
Antoine Duval ◽  
Sonia Molina-Boisseau ◽  
Christine Chirat
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Thermal Degradation ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Groups ◽  
Incomplete Removal ◽  
Phenolic Hydroxyl Groups

Abstract Commercial lignosulfonates (LS), recovered from bisulfite pulping processes, are known for their wide polydispersity. In this study, LS were fractionated by ultrafiltration (UF) and based on their solubility in ethanol (EtOH) solutions. The combination of both methods leads to a set of fractions of varying properties, suitable for several applications. UF gives well-separated fractions, with low polydispersity, and increasing functionality (sulfonate and phenolic hydroxyl groups) with decreasing molecular weight (MW). EtOH solubility yields more polydisperse fractions but still appears to be an easy and rapid way to obtain fractions with increasing MW. The residual sugars in LS, resulting from incomplete removal of hemicelluloses, were found to be mainly in the form of low MW oligomers, which were not bound chemically to lignin. Thermal degradation of the different fractions was also compared, giving better comprehension of the influence of the structure and composition. A glass transition temperature (Tg) could be measured for some fractions and was correlated to their MW.

Methylation of Phenolic Hydroxyl Group and Demethylation of Anisoles

2009 ◽  
Vol 2009 (4) ◽  
pp. 229-230 ◽  
Author(s):  
Nobuhiro Sato ◽  
Hiroyuki Endo
Keyword(s):  
Microwave Heating ◽  
Room Temperature ◽  
Reverse Reaction ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Phenolic Hydroxyl Groups ◽  
Phenyl Ethers ◽  
Methyl Phenyl

A mild methylation of phenolic hydroxyl groups with iodomethane was enabled in the presence of sodium bis(trimethylsilyl)amide at room temperature. The reverse reaction, namely demethylation of methyl phenyl ethers, was easily achieved by microwave heating with neat iodotrimethylsilane.

Fast, Easy, and Economical Quantification of Lignin Phenolic Hydroxyl Groups: Comparison with Classical Techniques

2018 ◽  
Vol 32 (5) ◽  
pp. 5969-5977 ◽  
Author(s):  
Luis Serrano ◽  
Esakkiammal Sudha Esakkimuthu ◽  
Nathalie Marlin ◽  
Marie-Christine Brochier-Salon ◽  
Gerard Mortha ◽  
...  
Keyword(s):  
Phenolic Hydroxyl ◽  
Hydroxyl Groups ◽  
Phenolic Hydroxyl Groups
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