Steric effects in the complexation kinetics of cyclic and open-chain polyamines with copper(II) in basic aqueous media

1975 ◽  
Vol 14 (4) ◽  
pp. 919-925 ◽  
Author(s):  
Chin-Tung. Lin ◽  
David B. Rorabacher ◽  
George R. Cayley ◽  
Dale W. Margerum
Keyword(s):  
Aqueous Media ◽  
Steric Effects ◽  
Open Chain ◽  
Kinetics Of ◽  
Complexation Kinetics

Complexation kinetics of highly substituted acyclic, monocyclic, and bicyclic tetraamines with copper(II) in basic aqueous media

1986 ◽  
Vol 25 (21) ◽  
pp. 3751-3757 ◽  
Author(s):  
Jane A. Drumhiller ◽  
Francois Montavon ◽  
Jean Marie Lehn ◽  
Richard W. Taylor
Keyword(s):  
Aqueous Media ◽  
Kinetics Of ◽  
Complexation Kinetics

Study of kinetics of reaction of lignin model compounds with propylene oxide

Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Krishna K. Pandey ◽  
Tapani Vuorinen
Keyword(s):  
Chemical Reaction ◽  
Propylene Oxide ◽  
Aqueous Media ◽  
Reaction Products ◽  
Model Compounds ◽  
Rapid Reduction ◽  
Visible Absorption ◽  
Lignin Model Compounds ◽  
Lignin Model ◽  
Kinetics Of

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.

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