Determination of mechanism functions and kinetic parameters of thermodecomposition of complexes with the Schiff base derived from 3-methoxysalicylaldehyde and diamine with non-isothermal TG and DTG curves

Abstract

The paper studies non-isothermal kinetics of monoaqua 3-methoxysalicylaldehyde- o-phenyldiamine copper(II) (cp1), 3-methoxysalicylaldehyde- o-phenyldiamine nickel(II) monohydrate (cp2), monoaqua 3-methoxysalicylaldehyde-ethyldiamine copper(II) (cp3) and 3-methoxysalicylaldehyde-ethyldiamine nickel(II) monohydrate (cp4) by use of non-isothermal TG and DTG curves. The kinetic parameters were analyzed by means of integral and differential methods, and mechanism functions of thermodecomposition reactions in their second steps were proposed. Thermodecomposition kinetic equations of the complexes are as follows: cp1: dα dt = Aexp ( − E RT ) × 1 cp2 and cp3: dα dt = Aexp ( − E RT )3/2(1−α)[−ln(1−α)] 1/3 cp4: dα dt = Aexp ( − E RT )2(1−α) 1/2 The corresponding kinetic compensation effect expressions of cp1–4 are found to be ln A = 0.2010 E + 0.5310, ln A = 0.1810 E − 0.3890, ln A = 0.1996 E − 0.8762 and ln A = 0.1800 E + 0.0789, respectively.