STUDY OF THE THERMAL-DECOMPOSITION OF CELLULOSE-HYPHAN AND ITS COMPLEXES WITH SOME TRANSITION AND INDIUM METAL-IONS

The studied complexes formed by the chelating ion exchanger were chara cterized by reflectance and infrared spectrometry. The thermal degrada tion of pure cellulose-hyphan (CH) and its complexes with Hg2+, In3+, Cr3+, Mo4+ and Mn2+ under an atmosphere of air has been studied using thermal gravimetry (TG) and differential thermal analysis (DTG). The r esults showed that four different stages are accompanying the decompos ition of (CH) and its complexes with the studied metals. These stages were found to be affected by the presence of the investigated metal io ns. On the bases of the applicability of a non-isothermal kinetic equa tion it was found to be a first-order reaction with the rate of degrad ation, k, ranging from 8.3.10(-5) to 6.2.10(-3) for (CH) and from 1.7. 10(-5) to 6.6.10(-3) s-1 for its complexes. The activation energy, E(a ), the entropy change, DELTAS-degree, the enthalpy change, DELTAH-degr ee and Gibbs free energy, DELTAG-degree are calculated by applying the rate theory of the first-order reaction. The effect of the different central metal ions on the calculated thermodynamic parameters is discu ssed.