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 ( E α ) 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 E α 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 E α has been developed. It shows very low relative errors in E α which are practically independent of x . The computations have been performed for model reactions as well as for the thermal decomposition of Cu 4 OCl 6 (triphenylphosphine oxide) 4 .