scholarly journals Transparent Cellulose/Technical Lignin Composite Films for Advanced Packaging

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1455 ◽  
Author(s):  
Guo ◽  
Tian ◽  
Shen ◽  
Yang ◽  
Long ◽  
...  
Keyword(s):  
Composite Films ◽  
Deep Eutectic Solvent ◽  
Value Added ◽  
Phenolic Hydroxyl ◽  
Total Phenolic ◽  
Hydroxyl Groups ◽  
Uv Shielding ◽  
Technical Lignin ◽  
Phenolic Hydroxyl Groups ◽  
Technical Lignins

Although recent work has shown natural lignin products are promising to fabricate various polymer based functional composites, high-value applications were challenged by their structural complexity and inhomogeneity. This work specially assessed the potential of four technical lignins for cellulose based functional films production. These four technical lignins were obtained by emerging pretreatment systems, i.e., lactic acid-betaine deep eutectic solvent (DES), ethanol organosolv, soda/anthraquinone (Soda/AQ) and the sodium salicylate hydrotrope, and their phenolic substructures were comparatively identified by prevalent 31P NMR technique. The influence of lignin chemical structure on the antioxidant potential and UV-shielding performance of the prepared cellulose/technical lignin composite films were assessed. Results showed severe organosolv and soda/AQ pretreatment produced technical lignins with higher total phenolic hydroxyl groups (3.37 and 3.23 mmol g-1 respectively), which also exhibited higher antioxidant activities. The composite films could effectively block the ultraviolet lights especially for UVB region (ultraviolet B, 280–315 nm) at only 5 wt.% lignin content. The contribution of lignin phenolic substructures to both antioxidant activity and UV-shielding property from high to low was syringyl > guaiacyl > p-hydroxyphenyl phenolic hydroxyl groups. This work provided some useful information that could facilitate upstream lignin extraction or downstream value-added applications.

Direct method for the determination of phenolic hydroxyl groups in pulp

Holzforschung ◽  
2007 ◽  
Vol 61 (6) ◽  
pp. 623-627 ◽  
Author(s):  
Tiina Liitiä ◽  
Tarja Tamminen
Keyword(s):  
Direct Method ◽  
Total Content ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Total Phenolic ◽  
Hydroxyl Groups ◽  
Peroxide Bleaching ◽  
Uv Reflectance ◽  
Phenolic Hydroxyl Groups ◽  
Reflectance Measurements

Abstract For evaluation of changes in phenolic lignin units during kraft pulping and bleaching, a direct method based on UV reflectance measurements of pulp handsheets was tested. Similar trends in total phenolic hydroxyl-group contents were evident when UV reflectance results for isolated lignins and pulp sheets were compared. This direct method gave reliable results after alkaline cooking, oxygen delignification, and bleaching stages followed by alkaline extraction (DE, ZE). However, the phenolic content obtained after peroxide bleaching (QP) was over-estimated. This may be due to alkali-induced reactions during pH adjustment of the sheets for measurement concomitant with ionisation of the phenolic hydroxyl groups. Otherwise, this direct method based on UV reflectance measurements is a promising new approach for determining the total content of phenolic lignin units in pulp sheets without isolating the lignin.

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
Sign in / Sign up

Export Citation Format

Share Document