Rice straw hydrotropic lignin was extracted from -Toluene sulfonic acid (-TsOH) fractionation with a different combined delignification factor (CDF). Hydrotropic lignin characterization was systematically investigated, and alkaline lignin was also studied for the contrast. Results showed that the hydrotropic rice straw lignin particle was in nanometer scopes. Compared with alkaline lignin, the hydrotropic lignin had greater molecular weight. NMR analysis showed that β-aryl ether linkage was well preserved at low severities, and the unsaturation in the side chain of hydrotropic lignin was high. H units and G units were preferentially degraded and subsequently condensed at high severity. High severity also resulted in the cleavage of part β-aryl ether linkage. P-NMR showed the decrease in aliphatic hydroxyl groups and the increasing carboxyl group content at high severity. The maximum weight loss temperature of the hydrotropic lignin was in the range of 330-350 °C, higher than the alkaline lignin, and the glass conversion temperature (T) of the hydrotropic lignin was in the range of 107-125 °C, lower than that of the alkaline lignin. The hydrotropic lignin has high β-aryl ether linkage content, high activity, nanoscale particle size, and low T, which is beneficial for its further valorization.
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http://dx.doi.org/10.3390/molecules26144123 | DOI Listing |
Int J Biol Macromol
December 2024
USDA Forest Service, Forest Products Laboratory, Madison, WI 53726, USA. Electronic address:
Improving flame retardancy and mechanical strength of lignin-containing polyurethane is a great challenge. In this study, lignin with favorable reactivity and dispersity was extracted from poplar using acid hydrotrope p-TsOH in EtOH. The extracted acid hydrotrope lignin (AHL) was subsequently functionalized with nitrogen and phosphorus (FHL) and reacted with isocyanate to fabricate a fire-retardant polyurethane (FHL-PU).
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Beijing Key Laboratory of Lignocellulosic Chemistry, Engineering Research Center of Forestry Biomass Materials and Energy, Ministry of Education, Beijing Forestry University, Beijing 100083, China. Electronic address:
Acidic hydrotropes exhibit effective performance in fractionating the constituents of lignocellulosic biomass owing to their amphiphilic characteristics. However, the requirement for excessively high concentrations may lead to the condensation and aggregation of lignin. In this case, bamboo was extracted with 70 % (w/v) tetrahydrofurfuryl alcohol (THFA) aqueous solution containing 5-20 % (w/v) p-toluenesulfonic acid (pTsOH) at 90-120 °C for 1-4 h.
View Article and Find Full Text PDFInt J Mol Sci
August 2024
Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China.
ChemSusChem
December 2024
Department of Molecular Sciences and Nanosystems, Università Ca' Foscari Venezia, Via Torino 155, 30172, Venice Mestre, Italy.
In contrast to conventional non-biobased adsorbents, lignin emerges as a cost-effective and environmentally benign alternative for water treatment. This study identifies unexpected and unpredicted multifunctional properties of lignin nanoparticles (LNPs). LNPs, which are prepared by simple physical processes, demonstrated for the first time to behave as multifunctional materials able to adsorb and photodegrade methylene blue (MB) in aqueous medium upon UV irradiation.
View Article and Find Full Text PDFACS Sustain Chem Eng
June 2024
CICECO, Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Lignin holds significant potential as a feedstock for generating valuable aromatic compounds, fuels, and functional materials. However, achieving this potential requires the development of effective dissolution methods. Previous works have demonstrated the remarkable capability of hydrotropes to enhance the aqueous solubility of lignin, an amphiphilic macromolecule.
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