Thermochimica Acta, Vol.419, No.1-2, 51-58, 2004
Analytical expressions of specific heat capacities for aqueous solutions of CMC and CPE
As previously reported, the influence of temperature and mass concentration on the specific heat capacity of two highly viscous solutions has been measured using adiabatic calorimetry. The absolute measurements were automated to operate steadily over the temperature range 290-360 K with an average heating rate of 8 x 10(-4) K s(-1). For both solutions of carboxy-methyl-cellulose (CMC) and carboxy-poly-ethylene (CPE), the evolution of specific heat capacities with temperature is compared with that of pure water. With CPE solutions, the increase of the temperature translated into an evolution of the C-p is comparable to the pure water with a value that varies with concentration. For CMC solutions, we observe the same temperature behaviour for a concentration of 83 g l(-1). For weaker concentrations, the influence of the temperature is different. To account for the influence of temperature and concentration parameters, we propose a correlation that facilitates the utilisation of these results corresponding to a relative error inferior to 2%. (C) 2004 Elsevier B.V. All rights reserved.
Keywords:adiabatic calorimeter;specific heat capacity;complex fluids;polynomial correlations;polymeric aqueous solutions