Qualitative and Quantitative Analysis of Lignin Produced from Beech Wood by Different Conditions of the Organosolv Process

Hansen, Basma; Kusch, Peter; Schulze, Margit; Kamm, Birgit

doi:10.1007/s10924-015-0746-3

Cited by 63 publications

(61 citation statements)

References 28 publications

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“…and procedure used for lignin isolation (kra, organosolv, ionic liquids etc.). As shown in previous studies for beech wood 81,82 and Miscanthus-derived lignins, [31][32][33][34]61 ethanol organosolv pre-treatment is an appropriate method to produce lignins of rather low molecular weight (MW) and narrow MW Fig. 6 Size exclusion chromatography results including the weight average molecular weight (MW, columns) and polydispersity index (PDI, squares) of lignins obtained from M. x giganteus and M. nagara, respectively, separated into leaves (Gig35 L, NagG10L) and stems (Gig35S, NagG10S).…”

Section: Lignin Molecular Weight and Polydispersitysupporting

confidence: 70%

Comparing chemical composition and lignin structure of Miscanthus x giganteus and Miscanthus nagara harvested in autumn and spring and separated into stems and leaves

et al. 2020

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Section: Lignin Molecular Weight and Polydispersitysupporting

confidence: 70%

Comparing chemical composition and lignin structure of Miscanthus x giganteus and Miscanthus nagara harvested in autumn and spring and separated into stems and leaves

et al. 2020

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“…National Renewable Energy Laboratory (NREL) proposed an accurate method for the determination of lignin, by which the absorbance of lignin was recorded at the recommended wavelength [54]. According to the intrinsic structure of lignin, several absorption maxima attributed to different functional groups were observed, as shown in Table 1 [25,30,50,[53][54][55][56]. The determination of phenolic hydroxyl groups can be achieved basing on the difference in absorption at 292 and 370 nm between phenolic units in neutral and alkaline solutions [30,50,55,56].…”

Section: Spectroscopic Methodsmentioning

confidence: 99%

Structural Characterization of Lignin and Its Degradation Products with Spectroscopic Methods

Hong-qin

et al. 2017

Journal of Spectroscopy

254

103

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Lignin is highly branched phenolic polymer and accounts 15-30% by weight of lignocellulosic biomass (LCBM). The acceptable molecular structure of lignin is composed with three main constituents linked by different linkages. However, the structure of lignin varies significantly according to the type of LCBM, and the composition of lignin strongly depends on the degradation process. Thus, the elucidation of structural features of lignin is important for the utilization of lignin in high efficient ways. Up to date, degradation of lignin with destructive methods is the main path for the analysis of molecular structure of lignin. Spectroscopic techniques can provide qualitative and quantitative information on functional groups and linkages of constituents in lignin as well as the degradation products. In this review, recent progresses on lignin degradation were presented and compared. Various spectroscopic methods, such as ultraviolet spectroscopy, Fourier-transformed infrared spectroscopy, Raman spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy, for the characterization of structural and compositional features of lignin were summarized. Various NMR techniques, such as 1 H, 13 C, 19 F, and 31 P, as well as 2D NMR, were highlighted for the comprehensive investigation of lignin structure. Quantitative 13 C NMR and various 2D NMR techniques provide both qualitative and quantitative results on the detailed lignin structure and composition produced from various processes which proved to be ideal methods in practice.

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“…Lignin, the most abundant natural resource next to cellulose and hemicellulose [1][2][3][4] contains various functional groups that provide active sites for chemical modification such as polarity adjustment to enhance the compatibility of lignin with other polymeric matrices in lignin/polymer composites [4,5] or to improve antioxidant properties [6][7][8][9][10][11]. Furthermore, studies reported lignin-derived encapsulation of various drugs for biomedical and agricultural applications.…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial Activity of Lignin-Derived Polyurethane Coatings Prepared from Unmodified and Demethylated Lignins

et al. 2019

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Due to global ecological and economic challenges that have been correlated to the transition from fossil-based to renewable resources, fundamental studies are being performed worldwide to replace fossil fuel raw materials in plastic production. One aspect of current research is the development of lignin-derived polyols to substitute expensive fossil-based polyol components for polyurethane and polyester production. This article describes the synthesis of bioactive lignin-based polyurethane coatings using unmodified and demethylated Kraft lignins. Demethylation was performed to enhance the reaction selectivity toward polyurethane formation. The antimicrobial activity was tested according to a slightly modified standard test (JIS Z 2801(JIS Z :2010. Besides effects caused by the lignins themselves, triphenylmethane derivatives (brilliant green and crystal violet) were used as additional antimicrobial substances. Results showed increased antimicrobial capacity against Staphylococcus aureus. Furthermore, the coating color could be varied from dark brown to green and blue, respectively.Coatings 2019, 9, 494 2 of 16 and DNA in cells of mice against oxidation damage [19] have been tested. Gao [20] and Bshena [21] studied the antimicrobial activity of various textiles, using lignin incorporated into polyethylene films and applied in the finishing processes. For textiles, there are special requirements such as non-toxicity to the consumer, namely cytotoxicity, allergy or irritation and sensitization. In other recent studies, lignosulfonic acid is reported to exhibit broad-spectrum anti-HIV (human immunodeficiency virus) and anti-HSV (herpes simplex virus) properties [22,23]. Thus, Qiu investigated the anti-HIV-1 activity-potential of lignosulfonates as a microbicide to prevent HIV-1 sexual transmission [23]. Another recently reported study revealed that the antimicrobial capacity of lignin correlates with the phenolic components, specifically the side chain structure and the nature of further functional groups [24]. Typically, the presence of a double bond in α, β positions of the side chain and a methyl group in the γ position grants the phenolic fragments with the most potency against microorganisms. However, none of the hitherto published studies included the investigation of the antibacterial activity of lignin when included in polymeric matrices.Unmodified lignin is widely studied as a component for polymer production with a focus on phenol-formaldehyde resins and polyurethanes (PUs) [25], where lignin is used as polyol substitute due to the high amount of hydroxyl groups resulting in high crosslinking densities and variable mechanical properties [26][27][28]. In previous studies, lignin-derived polyurethane coatings have been prepared using Kraft lignin isolated at room temperature from aqueous media (black liquor) at different pH values [29]. In addition, their antioxidative activity has been investigated using the Folin-Ciocalteu (FC) assay [30]. Although lignin contains many functionalities, they are often diff...

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Qualitative and Quantitative Analysis of Lignin Produced from Beech Wood by Different Conditions of the Organosolv Process

Cited by 63 publications

References 28 publications

Comparing chemical composition and lignin structure of Miscanthus x giganteus and Miscanthus nagara harvested in autumn and spring and separated into stems and leaves

Comparing chemical composition and lignin structure of Miscanthus x giganteus and Miscanthus nagara harvested in autumn and spring and separated into stems and leaves

Structural Characterization of Lignin and Its Degradation Products with Spectroscopic Methods

Antimicrobial Activity of Lignin-Derived Polyurethane Coatings Prepared from Unmodified and Demethylated Lignins

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