Acylation of cellulose in a novel solvent system: Solution of dibenzyldimethylammonium fluoride in DMSO

Casarano, Romeu; Pires, Paulo Augusto Rodrigues; Seoud, Omar A. El

doi:10.1016/j.carbpol.2013.09.043

Cited by 20 publications

(13 citation statements)

References 32 publications

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“…In the case of the dissolution with adjusted pH value applying NaOH, it could occur oxidative alkaline degradation. However, it is more likely that the electrolyte itself underwent Hofmann elimination and consequently led to degradation of cellulose, such observations were already described for quaternary ammonium salts by Casarano et al [32] After investigation of heating of pure N 2228 Cl, it was found that the solvent itself also changed color at elevated temperatures; see Figure 16. As shown in Figure 16, increasing the temperature to 120 °C and the long treatment of the solution at these conditions led to a change in color.…”

Section: Cellulose Degradationsupporting

confidence: 53%

Dissolution Capacity of Novel Cellulose Solvents Based on Triethyloctylammonium Chloride

Achtel

Jedvert

Kosan

et al. 2017

Macro Chemistry & Physics

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Dissolution of cellulose from various sources (microcrystalline cellulose and different dissolving grade pulp fibers) is investigated in solvent systems based on triethyl(n‐octyl)ammonium chloride (N2228Cl). Clear cellulose solutions are obtained with N2228Cl in a variety of solvents, e.g., dimethyl sulfoxide, N,N‐dimethylacetamide, and acetone. It is possible to prepare clear cellulose solutions from pulp fibers with concentrations up to 15 wt%. However, it is found that the cellulose is degraded, especially when neat (i.e., molten) N2228Cl is used as a solvent. The present work includes comprehensive rheological characterization of the cellulose solutions, both with shear and extensional rheology. In most cases, the viscosity values are low (complex viscosities below 100 Pa s for 5–10 wt% dissolved cellulose), and the solutions show more Newtonian than viscoelastic behavior.

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Section: Cellulose Degradationsupporting

confidence: 53%

Dissolution Capacity of Novel Cellulose Solvents Based on Triethyloctylammonium Chloride

Achtel

Jedvert

Kosan

et al. 2017

Macro Chemistry & Physics

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“…Part (A) indicates the simultaneous H-bonding of the oxygen atoms (red) of the acetate anion of diallylbenzylmethylammonium acetate (in IL-DMSO) to Cell-OH (unpublished results). Parts (B) and (C) are for cellulose dissolution by TBAF·3H 2 O/DMSO [84] and AlMeImCl-DMSO [73]; in both cases the halide ion is represented in green color. As can be seen, the AcO − anion from H-bonds to C 2 -OH and C 3 -OH of the same AGU ( Figure 10A, upper arrow) or two hydroxyl groups of adjacent AGU ( Figure 10A, lower arrow).…”

Section: Use Of Nmr and Theoretical Calculations To Assess Ionic Liqumentioning

confidence: 99%

Cellulose in Ionic Liquids and Alkaline Solutions: Advances in the Mechanisms of Biopolymer Dissolution and Regeneration

et al. 2019

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This review is focused on assessment of solvents for cellulose dissolution and the mechanism of regeneration of the dissolved biopolymer. The solvents of interest are imidazole-based ionic liquids, quaternary ammonium electrolytes, salts of super-bases, and their binary mixtures with molecular solvents. We briefly discuss the mechanism of cellulose dissolution and address the strategies for assessing solvent efficiency, as inferred from its physico-chemical properties. In addition to the favorable effect of lower cellulose solution rheology, microscopic solvent/solution properties, including empirical polarity, Lewis acidity, Lewis basicity, and dipolarity/polarizability are determinants of cellulose dissolution. We discuss how these microscopic properties are calculated from the UV-Vis spectra of solvatochromic probes, and their use to explain the observed solvent efficiency order. We dwell briefly on use of other techniques, in particular NMR and theoretical calculations for the same purpose. Once dissolved, cellulose is either regenerated in different physical shapes, or derivatized under homogeneous conditions. We discuss the mechanism of, and the steps involved in cellulose regeneration, via formation of mini-sheets, association into "mini-crystals", and convergence into larger crystalline and amorphous regions. We discuss the use of different techniques, including FTIR, X-ray diffraction, and theoretical calculations to probe the forces involved in cellulose regeneration.

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“…AlMeImF was obtained as given above (see Section 2.5); DMSO was added before the evaporation of methanol from the IL‐F solution, i.e., after its neutralization with HF 48. During this step, some DMSO was removed along with methanol (≤10%, by comparing the initial and final masses).…”

Section: Methodsmentioning

confidence: 99%

Successful Application of an Ionic Liquid Carrying the Fluoride Counter‐ion in Biomacromolecular Chemistry: Microwave‐Assisted Acylation of Cellulose in the Presence of 1‐Allyl‐3‐methylimidazolium Fluoride/DMSO Mixtures

Casarano

Seoud

2013

Macromolecular Bioscience

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The use of ionic liquids with fluoride anion (IL-F) is challenging because of side reactions. Neat 1-allyl-3-methylimidazolium fluoride (AlMeImF) is used as a solvent in microwave-assisted acylation of cellulose. The results are disappointing due to side reactions in the IL proper, and F(-) -mediated hydrolysis of the produced ester. A dramatic improvement is observed, when AlMeImF/DMSO mixture is employed. The results are comparable to those obtained when pure 1-allyl-3-methylimidazolium chloride is employed. FTIR spectroscopy shows that dissolving a carboxylic acid anhydride in IL-F leads to the formation of acyl fluoride. Thus ILs are far from being "spectator" solvents. The new approach (use of IL-F/DMSO) is attractive because of its efficiency, low cost, and applicability to the derivatization of any polymer.

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Acylation of cellulose in a novel solvent system: Solution of dibenzyldimethylammonium fluoride in DMSO

Cited by 20 publications

References 32 publications

Dissolution Capacity of Novel Cellulose Solvents Based on Triethyloctylammonium Chloride

Dissolution Capacity of Novel Cellulose Solvents Based on Triethyloctylammonium Chloride

Cellulose in Ionic Liquids and Alkaline Solutions: Advances in the Mechanisms of Biopolymer Dissolution and Regeneration

Successful Application of an Ionic Liquid Carrying the Fluoride Counter‐ion in Biomacromolecular Chemistry: Microwave‐Assisted Acylation of Cellulose in the Presence of 1‐Allyl‐3‐methylimidazolium Fluoride/DMSO Mixtures

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