Non-Isothermal Decomposition of Al, Cr and Fe Cross-Linked Trivalent Metal-Alginate Complexes

The thermal decomposition of al^iii, cr^iii and fe^iii metalalginate complexes have been investigated thermogravimetrically using (tg) and (dtg) techniques in static air. however, the tg curves showed three stages of weight loss, the dtg curves indicated the presence of a series of thermal peaks associated with the tg curves. the thermal dehydration of the coordinated water molecules was found to occur in the first stage, whereas the decomposition of the dehydrated complexes occurred in the second and third stages, respectively. the results revealed the formation of hydroxide, oxalate and carbonate for al^iii, cr^iii and feiii metal–alginate complexes, respectively, followed by decomposition of these intermediate fragments to the corresponding metal oxides as final products. these complexes have been characterized by ftir and chemical analysis. a tentative mechanism for decomposition has been suggested and discussed in terms of the strength of chelation and the structure geometry.