Study of kinetics of reaction of lignin model compounds with propylene oxide
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Krishna K. Pandey
Abstract
The etherification of phenolic groups has been found to inhibit photodegradation in wood and lignin rich pulps. The precise understanding of kinetics of chemical reaction between lignins or their model compounds and the etherifying agent is the first step for developing a viable modification procedure. In this study, we have investigated the reaction of lignin model compounds (namely, phenol and guaiacol) with propylene oxide in aqueous media. The kinetics of etherification reaction was studied under varying pH conditions in the temperature range 30–60°C. The etherified reaction products were characterized by gas chromatogram-mass spectrum (GC-MS). The extent of etherification of phenols and the rate of chemical reaction was followed by UV-Visible absorption spectroscopy. The reaction between lignin model compounds and propylene oxide was indicated by a rapid reduction in the absorbance accompanied by the development of a new band corresponding to etherified products. The reaction kinetics was investigated at pH ∼12 under the condition of excess concentration of propylene oxide. The reaction followed first order kinetics and rate constants increased linearly with an increase in the temperature and concentration of propylene oxide. The MS fragment data of reaction product support the proposed reaction scheme. The activation energy of the reaction of propylene oxide with phenol and guaiacol, calculated with the Arrhenius equation, was 56.2 kJ mol-1 and 45.4 kJ mol-1, respectively.
©2008 by Walter de Gruyter Berlin New York
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- Bagasse alkaline sulfite-anthraquinone (AS/AQ) pulping and totally chlorine free (TCF) bleaching
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- 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
