Physicochemical Properties and Structure of 1-Butyl-3-Methylimidazolium Methyl Sulfate

Russian Journal of Physical Chemistry A - Temperature dependences of density and dynamic viscosity are obtained for the ionic liquid 1-butyl-3-methylimidazolium methyl sulfate in the temperature...     

Oxidative delignification of wood in the supercritical carbon dioxide medium. 4. Acetylization of cellulose in the supercritical carbon dioxide medium

It is shown that cellulose can be acetylated with acetic anhydride in supercritical carbon dioxide in the absence of traditional catalysts, toxic solvents, and dilutants. As substrates, three cellulose samples were tested: sulfite and sulfate cellulose and cellulose obtained by low-temperature delignification in a supercritical carbon dioxide medium. The chemical composition of the cellulose diacetate product is characterized.     

The influence of supercritical carbon dioxide parameters on cellulose acetylization and properties of cellulose acetates

The possibility of cellulose diacetate production by direct acetylation of sulfite pulp with acetic anhydride in supercritical carbon dioxide (SC CO₂) is demonstrated. Optimum acetic anhydride to cellulose ratio and parameters of SC CO₂ are selected.     

Physicochemical properties of 1-butyl-3-methylimidazolium acetate

Characteristic IR and UV absorption bands, as well as oxidation half-wave potential on a platinum disc electrode in the cyclic mode were determined for the low-temperature hydrophilic ionic liquid 1-butyl-3-methylimidazolium acetate. Temperature dependences of the refractive index, density, and ansolute viscosity were determined in the temperature range 298–328 K. The activation energy of viscous flow was calculated.     

Thermophysical properties of model compounds of the lignin structural unit

Russian Chemical Bulletin - Sixteen lignin related aromatic compounds formed by the thermal degradation of lignin and being potentially valuable products of the processing of renewable raw...     

Calorimetric study of the interaction between lignin and aprotic solvents

Interaction of lignin with dimethyl formamide, dimethyl sulfoxide, and dioxane was studied by calorimetry. Concentration dependences of the enthalpy of interaction between lignin and aprotic solvents were obtained.     

Application of the interstice model to structure characterization of 1-butyl-3-methylimidazolium acetate

The structure of ionic liquid 1-butyl-3-methylimidazolium acetate was characterized by experimental physical parameters and on the basis of the interstice model.     

The oxidative delignification of wood in supercritical carbon dioxide: The functionalization of coniferous lignin

Changes in the content of lignin functional groups during low-temperature delignification under the action of hydrogen peroxide in supercritical (SC) CO₂ in the preparation of fibrous cellulose half-finished product were considered. The action of the oxidizer caused changes in the molecular weight characteristics of lignins. The experimental data showed the occurrence of both oxidation and substitution processes. Oxidation in SC CO₂ resulted in the formation of water- and alkali-soluble medium- and low-oxidized lignins because of decreased oxidizer consumption.     

The oxidative delignification of wood in supercritical carbon dioxide: 3. The chemical composition of fibrous half-finished products

The influence of pressure on the parameters of low-temperature oxidative delignification of firry wood in supercritical carbon dioxide under the action of hydrogen peroxide is described. The chemical composition of the cellulose half-finished products is characterized.     

An IR study of organosolvent lignin

The functional composition of lignin recovered from spruce wood and treated with alkali in aqueous and aqueous-ethanol medium and that of lignins recovered from alkaline cooking solutions in the presence of ethanol were studied by IR spectroscopy. The influence of ethanol on the content of the main functional groups in lignin was examinated.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 9, 2004, pp. 1547–1550.Original Russian Text Copyright © 2004 by Skrebets, Bogolitsyn, Kosyakov, Verbitskaya.