Kinetics of peroxodisulphate oxidations in t-butyl alcohol–water solvent mixtures

1968 ◽  
Vol 0 (0) ◽  
pp. 2571-2575 ◽  
Author(s):  
J. Burgess
Keyword(s):  
Butyl Alcohol ◽  
Solvent Mixtures ◽  
Water Solvent ◽  
Alcohol Water ◽  
Kinetics Of

Solubility and Thermoresponsiveness of PMMA in Alcohol-Water Solvent Mixtures

2010 ◽  
Vol 63 (8) ◽  
pp. 1173 ◽  
Author(s):  
Richard Hoogenboom ◽  
C. Remzi Becer ◽  
Carlos Guerrero-Sanchez ◽  
Stephanie Hoeppener ◽  
Ulrich S. Schubert
Keyword(s):  
Methyl Methacrylate ◽  
Pure Water ◽  
Polymer Concentration ◽  
Polymer Processing ◽  
Solution Temperature ◽  
Solvent Mixtures ◽  
Poly Methyl Methacrylate ◽  
Water Solvent ◽  
Alcohol Water ◽  
Hysteresis Behaviour

To reduce the environmental burden of polymer processing, the use of non-toxic solvents is desirable. In this regard, the improved solubility of poly(methyl methacrylate) (PMMA) in ethanol/water solvent mixtures is very appealing. In this contribution, detailed investigations on the solubility of PMMA in alcohol/water solvent mixtures are reported based on turbidimetry measurements. PMMA revealed upper critical solution temperature transitions in pure ethanol and ethanol/water mixtures. However, around 80 wt-% ethanol content a solubility maximum was observed for PMMA as indicated by a decrease in the transition temperature. Moreover, the transition temperatures increased with increasing PMMA molar mass as well as increasing polymer concentration. Careful analysis of both heating and cooling turbidity curves revealed a peculiar hysteresis behaviour with a higher precipitation temperature compared with dissolution with less than 60 wt-% or more than 90 wt-% ethanol in water and a reverse hysteresis behaviour at intermediate ethanol fractions. Finally, the transfer of poly(styrene)-block-poly(methyl methacrylate) block copolymer micelles from the optimal solvent, i.e. aqueous 80 wt-% ethanol, to almost pure water and ethanol is demonstrated.

Chlorine isotope effects in the solvolysis of substituted 1-phenylethyl chlorides

1986 ◽  
Vol 64 (6) ◽  
pp. 1201-1205 ◽  
Author(s):  
Duncan J. McLennan ◽  
Allan R. Stein ◽  
Brian Dobson
Keyword(s):  
Transition State ◽  
Theoretical Calculations ◽  
Isotope Effects ◽  
Chloride Ion ◽  
Solvent Composition ◽  
Solvent Mixtures ◽  
Chlorine Isotope ◽  
Water Solvent ◽  
Alcohol Water ◽  
Substituted 1

Kinetic chlorine isotope effects attending the solvolysis of several ring-substituted 1-phenylethyl chlorides in alcohol–water solvent mixtures are reported. The k35/k37 values are insensitive to the identity of ring substituents and to solvent composition. Results are interpreted in terms of an SN1 heterolytic process incorporating a significant amount of internal return. Theoretical calculations suggest that the incipient chloride ion in the transition state may be strongly hydrogen-bonded.

Kinetics of oxidation of the bis(ethylenediamine)mercaptoacetatocobalt(III) and cysteinato-bis(ethylenediamine)cobalt(III) ions by hydrogen peroxide in mixed aqueous-nonaqueous solutions

1988 ◽  
Vol 53 (3) ◽  
pp. 554-562
Author(s):  
Ján Benko ◽  
Oľga Vollárová ◽  
Miroslav Kovarčík
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Butyl Alcohol ◽  
Acid Base ◽  
Kinetics Of Oxidation ◽  
Tert Butyl Alcohol ◽  
Alcohol Water ◽  
Acid Base Equilibrium ◽  
Kinetics Of

The kinetics of oxidation of the coordinatively bonded sulphur in the cysteinato-bis(ethylenediamine)cobalt(III) and bis(ethylenediamine)mercaptoacetatocobalt(III) complexes by hydrogen peroxide to the sulphoxides was examined in HClO4 solutions (c(HClO4) = 1 – 500 mmol l-1) with a view to obtaining data characterizing the effect of the acid-base equilibria of the reactants on the reaction rate. The reaction rate was found affected particularly by the acid-base equilibrium of the oxidant, which plays a role in strongly acid solutions. The oxidation was also studied in water-methyl alcohol, water-tert-butyl alcohol and water-ethylene glycol mixtures, and the effect of the mole fraction of the nonaqueous component on the rate constant and thermodynamic activation parameters was examined.

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