The effect of thermal degradation on the equilibrium constant (K) and enthalpy values for the ion exchange reactions were carried out at different temperatures to predict the selectivity behaviour of ion exchange resins DuoliteARA-9366 towards iodide and bromide ions in solution. The resin was thermally degraded at different degradation temperatures of 70.0o C, 100.0o C and 120.0o C. The experiment was extended further by performing the above ion exchange reaction using thermally degraded ion exchange resins DuoliteARA-9366. The standard enthalpy values of the above ion exchange reaction performed by using fresh and degradedresins DuoliteARA-9366 at 70.0o C, 100.0o C and 120.0o C were calculated as-47.87,-18.79, -9.50, -15.63 kJ/mole for Cl- /I- and for Cl- /Brwere -14.77,-4.71,-10.89,-6.84 kJ/mole respectively. The thermodynamic data obtained here reveal that iodide ions were more selective towards the resin surface compared to bromide ions. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) was used to characterize the resins degradation steps.
