Kinetics and Mechanism of Non-Isothermal Decomposition of Some Cross-Linked Metal-Alginate Complexes Especially Trivalent Metal -Alginate Complexes

The kinetics of thermal decomposition of AlIII -, CrIII -, FeIII ,CeIII and LaIII -alginate complexes have been studied using thermogravimetry (TG) and differential thermogravimetry (DTG) techniques in static air. However, the TG curves showed three distinct stages of weight loss, the DTG curves indicated the presence of a series of thermal peaks associated with the TG curves. The results reveal that the thermal decomposition of each complex proceeds by dehydration of four coordinated water molecules in the first step whereas the decomposition of the formed dehydrated complexes occurs in the following two steps, respectively. The kinetic parameters were computed by a set of different models and a tentative decomposition mechanism in good consistent with the kinetic observations is discussed.