Using Fractionation and Diffusion Ordered Spectroscopy to Study Lignin Molecular Weight.

Montgomery, James R. D.; Bazley, Priory; Lébl, Tomáš; Westwood, Nicholas J.

doi:10.1002/open.201900129

Cited by 16 publications

(17 citation statements)

References 47 publications

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“…[104,192,193] Other techniques can be applieds uch as MALDI, [194] but also DOSY NMR. [179,195] Identification and quantification of specific functional groups in lignin such as ketones,a lcohols/phenols, and carboxylic acids such as titrationsc an be performed using titrations, [196] FTIR spectroscopy, [20] or specific reagents in combination with 31 Pa nd 19 FNMR spectroscopy [197,198] The application of smaller (typically dimeric) model compounds differs significantly from those of larger oligomeric and polymericm odel compounds. Already simple dimeric model compounds can be applied to excellent effect in the development of new catalytic methodologies for the breakdown of specific linking motifs,i dentify potentiald epolymerization products, or to elucidate the effect of chemical treatment on the lignin structure.…”

Section: Concluding Considerations For Using Lignin Model Compounds Fmentioning

confidence: 99%

“…For more specific information on the size of extracted lignins as well as larger model compounds researchers turn to size‐exclusion chromatography, although the molecular weight data obtained highly dependd on the system and standards used in combination with the mobile phase . Other techniques can be applied such as MALDI, but also DOSY NMR . Identification and quantification of specific functional groups in lignin such as ketones, alcohols/phenols, and carboxylic acids such as titrations can be performed using titrations, FTIR spectroscopy, or specific reagents in combination with 31 P and 19 F NMR spectroscopy…”

Section: Concluding Considerations For Using Lignin Model Compounds Fmentioning

confidence: 99%

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An Introduction to Model Compounds of Lignin Linking Motifs; Synthesis and Selection Considerations for Reactivity Studies

et al. 2020

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The development of fundamentally new valorization strategies for lignin plays a vital role in unlocking the true potential of lignocellulosic biomass as sustainable and economically compatible renewable carbon feedstock. In particular, new catalytic modification and depolymerization strategies are required. Progress in this field, past and future, relies for a large part on the application of synthetic model compounds that reduce the complexity of working with the lignin biopolymer. This aids the development of catalytic methodologies and in‐depth mechanistic studies and guides structural characterization studies in the lignin field. However, due to the volume of literature and the piecemeal publication of methodology, the choice of suitable lignin model compounds is far from straight forward, especially for those outside the field and lacking a background in organic synthesis. For example, in catalytic depolymerization studies, a balance between synthetic effort and fidelity compared to the actual lignin of interest needs to be found. In this Review, we provide a broad overview of the model compounds available to study the chemistry of the main native linking motifs typically found in lignins from woody biomass, the synthetic routes and effort required to access them, and discuss to what extent these represent actual lignin structures. This overview can aid researchers in their selection of the most suitable lignin model systems for the development of emerging lignin modification and depolymerization technologies, maximizing their chances of successfully developing novel lignin valorization strategies.

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Section: Concluding Considerations For Using Lignin Model Compounds Fmentioning

confidence: 99%

Section: Concluding Considerations For Using Lignin Model Compounds Fmentioning

confidence: 99%

An Introduction to Model Compounds of Lignin Linking Motifs; Synthesis and Selection Considerations for Reactivity Studies

et al. 2020

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“…After solvent fractionation of several bulk lignins, leading to samples with a relatively low polydispersity of ca. 2, the MHS equation could be applied to the relation of M w and D . Similarly, lignin samples fractionated by GPC have been used to perform a calibration, but here the diffusion coefficients were extrapolated to infinite dissolution ( D 0 ) …”

Section: Introductionmentioning

confidence: 99%

Is NMR Combined with Multivariate Regression Applicable for the Molecular Weight Determination of Randomly Cross-Linked Polymers Such as Lignin?

et al. 2021

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The molecular weight properties of lignins are one of the key elements that need to be analyzed for a successful industrial application of these promising biopolymers. In this study, the use of 1H NMR as well as diffusion-ordered spectroscopy (DOSY NMR), combined with multivariate regression methods, was investigated for the determination of the molecular weight (M w and M n) and the polydispersity of organosolv lignins (n = 53, Miscanthus x giganteus, Paulownia tomentosa, and Silphium perfoliatum). The suitability of the models was demonstrated by cross validation (CV) as well as by an independent validation set of samples from different biomass origins (beech wood and wheat straw). CV errors of ca. 7–9 and 14–16% were achieved for all parameters with the models from the 1H NMR spectra and the DOSY NMR data, respectively. The prediction errors for the validation samples were in a similar range for the partial least squares model from the 1H NMR data and for a multiple linear regression using the DOSY NMR data. The results indicate the usefulness of NMR measurements combined with multivariate regression methods as a potential alternative to more time-consuming methods such as gel permeation chromatography.

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“…Some studies already addressed the potential of DOSY showing the separation of phenol, guaiacol, and 2,6-dimethoxyphenol from a mixture prepared from commercial standards . More recently, good correlations of the apparent masses measured by SEC and DOSY were obtained for lignin fractions with narrow molecular weight distributions. , However, few studies were published using conventional 1 H-DOSY or 31 P-DOSY ,, to estimate the molecular weight in depolymerization reaction mixtures using DOSY.…”

Section: Introductionmentioning

confidence: 99%

“…30 More recently, good correlations of the apparent masses measured by SEC and DOSY were obtained for lignin fractions with narrow molecular weight distributions. 34,35 However, few studies were published using conventional 1 H-DOSY or 31 P-DOSY 23,36,37 to estimate the molecular weight in depolymerization reaction mixtures using DOSY.…”

Section: ■ Introductionmentioning

confidence: 99%

Systematic Diffusion-Ordered Spectroscopy for the Selective Determination of Molecular Weight in Real Lignins and Fractions Arising from Base-Catalyzed Depolymerization Reaction Mixtures

Cornejo

García‐Yoldi

Alegría-Dallo

et al. 2020

ACS Sustainable Chem. Eng.

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The valorization of biorefinery downstream lignin fractions is a key issue in order to increase the sustainability of Second Generation Biofuels. The development of reliable methodologies for the selective determination of apparent masses of the poly-(hydroxy)aromatic ethers arising from lignin depolymerization reaction is crucial. Diffusion Ordered Spectroscopy (DOSY) has been tested to estimate the molecular weight in biorefinery downstream lignins and base catalyzed depolymerization reaction mixtures. Excellent correlation was found in the calibration of molecular weight and diffusion coefficients with standards. DOSY permitted the selective estimation of the apparent masses of different fractions in the lignin and in the depolymerization reaction mixtures, providing a more profound knowledge of the reaction mixture composition than traditional Size Exclusion Chromatography (SEC). Excellent correlations have been achieved in the estimation of the apparent masses of poly-(hydroxy)-aromatic ethers between SEC and DOSY. This permits a reliable estimation of the molecular weight of different fractions in the lignin and in the depolymerization product, which is essential for their further applications.

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Using Fractionation and Diffusion Ordered Spectroscopy to Study Lignin Molecular Weight.

Cited by 16 publications

References 47 publications

An Introduction to Model Compounds of Lignin Linking Motifs; Synthesis and Selection Considerations for Reactivity Studies

An Introduction to Model Compounds of Lignin Linking Motifs; Synthesis and Selection Considerations for Reactivity Studies

Is NMR Combined with Multivariate Regression Applicable for the Molecular Weight Determination of Randomly Cross-Linked Polymers Such as Lignin?

Systematic Diffusion-Ordered Spectroscopy for the Selective Determination of Molecular Weight in Real Lignins and Fractions Arising from Base-Catalyzed Depolymerization Reaction Mixtures

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