Esterification of carboxylic acids on cellulosic material: Solid state reactions
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Anna Pantze
Abstract
In the present work, the formation of ester linkages in cellulosic materials during drying and heating was addressed. The results indicated that direct ester formation, without anhydride intermediate, occurs between carboxylic acids of suitable structure and cellulosic hydroxyls at 180°C, even after reaction times as short as 5 min. The 2(R)-hydroxybutyric acid is most effective in ester formation, followed by 2-ketobutyric acid and 3-hydroxybutyric acid. Hexanoic acid is less effective and veratric acid produces no esters at all. At lower temperatures, 2-ketobutyric acid is the most reactive compound. One conclusion is that a hydroxyl or keto group in α position of the carboxylic acids favours ester formation. Another finding is that three pyrrolidine structures are produced after esterification and aminolysis of 2-ketobutyric acid. One of the structures indicates that 2-ketobutyric acid is reactive in two positions and could therefore be a potential cross-linker. A critical parameter for ester formation is pH, and the results indicate that pH <2 strongly favours esterification, whereas almost no esters are produced at pH >5–6. All experiments were performed in a solid-state model system (on cellulosic filter paper) with low moisture content. Esterification of five carboxylic acids was studied. Samples were heated constantly at 180°C for 5 min or gradually from 22°C to 180°C over periods ranging from 5 to 45 min. Quantitative analysis of ester formation between the monocarboxylic acids and the hydroxyl groups of cellulose was performed by means of aminolysis and gas chromatography.
©2008 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Meetings
- Cellulose aerogels: Highly porous, ultra-lightweight materials
- Esterification of carboxylic acids on cellulosic material: Solid state reactions
- Bagasse alkaline sulfite-anthraquinone (AS/AQ) pulping and totally chlorine free (TCF) bleaching
- Effect of abnormal fibres on the mechanical properties of paper made from Norway spruce, Picea abies (L.) Karst.
- Development of fully bio-based composite: Wood/cellulose diacetate/poly(lactic acid) composite
- Crystallinity and mesoporosity of carbon produced from ligno-p-cresol and their improvement by pulverization and acid treatment
- Revisiting the mechanism of β-O-4 bond cleavage during acidolysis of lignin. Part 1: Kinetics of the formation of enol ether from non-phenolic C6-C2 type model compounds
- Study of kinetics of reaction of lignin model compounds with propylene oxide
- Two-dimensional homo- and hetero-correlation technique applied to NIR and py-MBMS spectra of wood
- UV resonance Raman spectroscopic study of photodegradation of hardwood and softwood lignins by UV laser
- A multivariate approach to the acetylated poplar wood samples by near infrared spectroscopy
- Structure elucidation of phenylethanoid glycosides from Paulownia tomentosa Steud. var. tomentosa wood
- A generalized mat consolidation model for wood composites
- Prediction and optimization of surface roughness in milling of medium density fiberboard (MDF) based on Taguchi orthogonal array experiments
- An investigation on the permeability of different wood furnish materials
- Laccase-catalyzed functionalization with 4-hydroxy-3-methoxybenzylurea significantly improves internal bond of particle boards
- Effect of thermo-mechanical refining pressure on the properties of wood fibers as measured by nanoindentation and atomic force microscopy
- Adhesive bond strength of end grain joints in softwood with varying density
- An experimental study of the effects of moisture variations and gradients in the joint area in steel-timber dowel joints
- A new image analysis algorithm for calculating percentage wood failure
- Dr. Gordon Leary
Articles in the same Issue
- Meetings
- Cellulose aerogels: Highly porous, ultra-lightweight materials
- Esterification of carboxylic acids on cellulosic material: Solid state reactions
- Bagasse alkaline sulfite-anthraquinone (AS/AQ) pulping and totally chlorine free (TCF) bleaching
- Effect of abnormal fibres on the mechanical properties of paper made from Norway spruce, Picea abies (L.) Karst.
- Development of fully bio-based composite: Wood/cellulose diacetate/poly(lactic acid) composite
- Crystallinity and mesoporosity of carbon produced from ligno-p-cresol and their improvement by pulverization and acid treatment
- Revisiting the mechanism of β-O-4 bond cleavage during acidolysis of lignin. Part 1: Kinetics of the formation of enol ether from non-phenolic C6-C2 type model compounds
- Study of kinetics of reaction of lignin model compounds with propylene oxide
- Two-dimensional homo- and hetero-correlation technique applied to NIR and py-MBMS spectra of wood
- UV resonance Raman spectroscopic study of photodegradation of hardwood and softwood lignins by UV laser
- A multivariate approach to the acetylated poplar wood samples by near infrared spectroscopy
- Structure elucidation of phenylethanoid glycosides from Paulownia tomentosa Steud. var. tomentosa wood
- A generalized mat consolidation model for wood composites
- Prediction and optimization of surface roughness in milling of medium density fiberboard (MDF) based on Taguchi orthogonal array experiments
- An investigation on the permeability of different wood furnish materials
- Laccase-catalyzed functionalization with 4-hydroxy-3-methoxybenzylurea significantly improves internal bond of particle boards
- Effect of thermo-mechanical refining pressure on the properties of wood fibers as measured by nanoindentation and atomic force microscopy
- Adhesive bond strength of end grain joints in softwood with varying density
- An experimental study of the effects of moisture variations and gradients in the joint area in steel-timber dowel joints
- A new image analysis algorithm for calculating percentage wood failure
- Dr. Gordon Leary
