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  • 1 Gerhard-Mercator-Universität Duisburg Institut für Chemie, Fakultät 4 47048 Duisburg Germany 47048 Duisburg Germany
  • 2 Fachgebiet: Angewandte Physikalische Chemie Germany Germany
  • 3 Optek-Danulat 279 South 17th Avenue, Suite 10 West Bend WI 53095 USA 279 South 17th Avenue, Suite 10 West Bend WI 53095 USA
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Abstract  

A method has been developed that utilizes a special custom-made mixing device and HPLC micro liter syringe to perform mixing experiments of liquid systems directly in open measuring cells of differential scanning calorimeters. The present paper describes how to determine mixing enthalpies from time scans of the isothermal heat flux during an exothermal or endothermal process. Using ethylene glycol and the slightly volatile component water to calibrate the mixing calorimeter, the mixing enthalpy of the binary system poly(ethylene glycol) 400/water could be determined with sufficient precision compared to the results of measurements with a conventional flow calorimeter.