Linear and Nonlinear Procedures in Isoconversional Computations of the Activation Energy of Nonisothermal Reactions in Solids

Abstract

An integral isoconversional method provides a linear procedure to estimate the activation energy (Eα) at a given conversion (α) but only when an oversimplified approximation of the temperature integral (p(x), where x = E/RT, R is the gas constant and T is the temperature) is used. Although the relative error in Eα is several times less than the relative error in p(x) it happens to be substantial at x < 13. In the present study a nonlinear procedure to estimate Eα has been developed. It shows very low relative errors in Eα which are practically independent of x. The computations have been performed for model reactions as well as for the thermal decomposition of Cu4OCl6(triphenylphosphine oxide)4.