Revealing the structure-activity relationship between lignin and anti-UV radiation

Lin, Minsheng; Yang, Linjie; Zhang, Han; Xia, Yafeng; He, Ying; Lan, Wu; Ren, Junli; Yue, Fengxia; Lu, Fachuang

doi:10.1016/j.indcrop.2021.114212

Cited by 71 publications

(33 citation statements)

References 32 publications

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“…The peak at δC/δH 55.6/3.72 ppm was assigned to the methoxyl group. The peaks at δC/δH 110.9/6.95 ppm, δC/δH 114.6/6.70 ppm, and δC/δH 119.1/6.78 ppm were assigned to G2, G5 and G6, respectively (Mansfield et al 2012;Lin et al 2021;Su et al 2021). The peak at δC/δH 103.8/6.68 ppm was assigned to S2, 6.…”

Section: Molecular Weight Analysismentioning

confidence: 99%

Structural characteristics of eucalyptus lignin regulated through alkali cooking process

Shen

Liu

Wei

et al. 2022

BioRes

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Understanding the basic chemical structure of lignin macromolecules can facilitate the development of lignin-based materials. In this study, the lignin structure was regulated through different alkali cooking conditions. The acid precipitated lignin from the spent cooking liquor was purified and fractionated with different organic solvents. The lignin samples with different structures were obtained by regulating the cooking time. The structural characteristics of the lignin preparations were systematically investigated. The results revealed that the structure of lignin was regulated by the heating time and the residence time during the cooking process. Non-condensed lignin was achieved after a specific cooking condition; it had higher molecular weight (9686 g/mol), more β-O-4 linkages (25.3/100Ar), but lower phenolic hydroxyl content (1.51 mmol/g) than the counterpart pulping with longer time duration. The non-condensed lignin also had excellent thermal stability. Compared with industrial lignin, the lignin with non-condensed structure can be modified to obtain phenolic resin materials with better performance. The non-condensed structure with the specific characteristics can broaden the valorization of lignin for producing biochemical and biomaterials.

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Section: Molecular Weight Analysismentioning

confidence: 99%

Structural characteristics of eucalyptus lignin regulated through alkali cooking process

Shen

Liu

Wei

et al. 2022

BioRes

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“…KL is an excellent UV barrier due to the formation of unsaturated ethylene groups and condensed structures, while the intermolecular β–O–4 linkages were cleaved during the pulping process . This UV-blocking function can be imparted to KL-based composites. , In the current study, all the prepared lignin -g- PCL films, including both the nonfractionated and fractionated lignin precursors used, can effectively shield broad-spectrum UV radiation including UV-A (wavelength at 400–320 nm), UV-B (wavelength at 320–280 nm), and UV-C (wavelength at 280–200 nm) regions; on the contrary, the half-transparent neat PCL film shows inferior UV-shielding performance (Figure C).…”

Section: Resultsmentioning

confidence: 81%

Effect of the Lignin Structure on the Physicochemical Properties of Lignin-Grafted-Poly(ε-caprolactone) and Its Application for Water/Oil Separation

Xie

Meng

et al. 2022

ACS Sustainable Chem. Eng.

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Lignin-grafted poly(ε-caprolactone) copolymers (lignin-g-PCLs) have shown wide application potentials in coatings, biocomposites, and biomedical fields. However, the structural heterogeneity of lignin affecting the structures and properties of lignin-g-PCL has been scarcely investigated. Herein, kraft lignin is fractionated into four precursors, namely, Fins, F1, F2, and F3, with declining molecular weights and increased hydroxyl contents. Lignin-g-PCLs are synthesized via ring-opening polymerization of ε-caprolactone with lignin and characterized by GPC, FTIR, 1H and 31P NMR, DSC, TGA, and iGC. The mechanical properties, UV barrier, and enzymatic biodegradability of the lignin-g-PCLs are evaluated. Results show that lignin with a higher molecular weight and aliphatic OH favors the copolymerization, leading to lignin-g-PCLs with longer PCL arms. Moreover, lignin incorporation improves the thermal stability, hydrophobicity, and UV-blocking ability but reduces the lipase hydrolyzability of the copolymers. We also demonstrated that the lignin-g-PCL-coated filter paper could successfully separate chloroform–, petroleum ether–, and hexane–water mixtures with an efficiency up to 99.2%. The separation efficiency remains above 90% even after 15 cycles. The structural differences of copolymers derived from the fractionation showed minimal influence on the separation efficiency. This work provides new insights into lignin-based copolymerization and the versatility of lignin valorization.

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“…Anti-UV nanofillers such as TiO 2 , ZnO, etc., can absorb UV energy by internal electron leap from the valence band to conduction band and convert it to other energy releases with less energy, thus playing the role of UV absorption and shielding. , However, the addition of functional fillers may damage the mechanical properties of the composites and strongly reduce the light transmittance in the visible range, resulting in opaque composites and thus limiting the application scope. Bio-based molecules such as lignin, curcumin, and quercetin contain UV-absorbing functional groups such as phenols, ketones, conjugated double bonds, and other chromophore groups. , Adding antioxidant molecules extracted from plants to PU can improve the UV resistance and mechanical strength. − However, these biological antioxidant molecules usually have color, which will inevitably lead to colored PU composites, thus limiting their applications. Oprea and Potolinca prepared a series of intrinsic anti-UV polyurethanes using 2,2′-dihydroxy-4-methoxybenzophenone (DHMB, an organic sunscreen compound) as a chain extender.…”

Section: Introductionmentioning

confidence: 99%

“…Biobased molecules such as lignin, curcumin, and quercetin contain UV-absorbing functional groups such as phenols, ketones, conjugated double bonds, and other chromophore groups. 32,33 Adding antioxidant molecules extracted from plants to PU can improve the UV resistance and mechanical strength. 22−24 However, these biological antioxidant molecules usually have color, which will inevitably lead to colored PU composites, thus limiting their applications.…”

Section: Introductionmentioning

confidence: 99%

Colorless, Transparent, and High-Performance Polyurethane with Intrinsic Ultraviolet Resistance and Its Anti-UV Mechanism

Huang

Yao

Huang

et al. 2023

ACS Appl. Mater. Interfaces

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Polyurethane (PU) is a widely used polymer material that will age under prolonged exposure to ultraviolet (UV) light, shortening the service life. Several methods have been used to prepare the anti-UV PU, including adding nonreactive anti-UV additives, functional fillers, and biological antioxidant molecules. However, the nonreactive anti-UV additives may migrate during long-term use, the functional fillers may damage the mechanical properties and seriously reduce the light transmittance of the sample, and the biological antioxidant molecules will inevitably color the sample. To solve these problems, in this work, a benzotriazole UV absorber (Chiguard R-455) was introduced into the PU molecular chains by in situ polymerization to prepare the nonmigrating intrinsic anti-UV PU sample with high performance and colorless transparency. The anti-UV PU samples exhibit light transmittance of over 88% in the visible range and superior mechanical properties with tensile strength higher than 65 MPa and elongation at break higher than 900%. After 24 h UV irradiation (200 W, 365 nm), the tensile strength and elongation at break of pure PU sample are significantly reduced to only 8.9 and 15.8% of the original one, respectively. On the contrary, the addition of Chiguard R-455 will endow the PU sample with excellent anti-UV performance. After 24 h UV irradiation, the tensile strength (67.2 ± 1.6 MPa) and elongation at break (917.4 ± 30.0%) of PU-0.5% (the content of Chiguard R-455 is only 0.5 wt %) have changed little compared with the sample without irradiation (67.4 ± 3.5 MPa and 919.4 ± 26.5%). Additionally, the anti-UV mechanism of the PU sample is systematically studied. This work provides a feasible method for preparing colorless, transparent, high-performance, nonmigrating intrinsic UV-shielding PU samples, which can be used as a UV light-shielding material in various fields with visible and aesthetic requirements, such as protection fields and wearable products.

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Revealing the structure-activity relationship between lignin and anti-UV radiation

Cited by 71 publications

References 32 publications

Structural characteristics of eucalyptus lignin regulated through alkali cooking process

Structural characteristics of eucalyptus lignin regulated through alkali cooking process

Effect of the Lignin Structure on the Physicochemical Properties of Lignin-Grafted-Poly(ε-caprolactone) and Its Application for Water/Oil Separation

Colorless, Transparent, and High-Performance Polyurethane with Intrinsic Ultraviolet Resistance and Its Anti-UV Mechanism

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