STUDY OF KINETICS OF THERMAL-DECOMPOSITION OF URANYL-NITRATE COMPLEXES WITH N-ALKYLCAPROLACTAMS BY MEANS OF NONISOTHERMAL GRAVIMETRY

The kinetics of thermal decomposition of a series of uranyl nitrate complexes with N-alkyl-caprolactams (alkyl=C2H5, C4H9, C6H13, C8H17, C10H21 or C12H25) was studied by means of non-isothermal gravimetry under a nitrogen atmosphere. From the TG-DTG curves, the kinetic parameters relating to the loss of two molecules of coordinated ligand were obtained by employing two groups of methods: (I) a group of conventional methods involving the Coats-Redfern, Freeman-Carroll, Horowitz-Metzger, Dharwadkar-Karkhanavala and Doyle (modified by Zsako) equations; (II) a hew method were suggested by J. Malek et al. The results obtained using two types of methods were compared, and it emerged that the results of method II were much more meaningful and reasonable in this work. Additionally, the effects of the molecular structure of the ligands on the kinetic data and models were studied and are discussed.