Abstract:
This paper is a logical continuation of the previous review by the authors and reflects the present state of studies on the thermal stability of anion-exchange materials. It deals with the principal methods for the investigation of the thermal stability of anion-exchange resins and presents rational formulae for the recalculation of exchange capacities which facilitate comparison of the experimental data of different investigators. Attention has been concentrated on a general description of data on the thermal stability of different anion-exchange resins in air, in water and aqueous solutions, and in organic and mixed media. A new mechanism is proposed for processes involving changes in ion-exchange resins in the above media. Rigorous kinetic equations describing the decrease of the exchange capacity with respect to highly basic groups, deamination, and degradation of the amino-groups in anion-exchange resins have been obtained on its basis and agree satisfactorily with the experimental data. Further aims of studies on the thermal stability of ion-exchange resins have been outlined. The bibliography includes 112 references.