Thermodynamics and Kinetics of the p-tert-Butylcalix[4]arenes Decomposition Process

Abstract

p-tert-Butylcalix[n]arenes (PTB-C4) were synthesized and characterized. The thermal properties of PTB-C4 were investigated with thermogravimetric analysis (TGA) and differential thermal gravity (DTG). TGA and DTG curves of PTB-C4 indicate that the decomposition process of PTB-C4 includes 2 stages: the de-tert-butylation decomposition stage (1st decomposition stage) and the ring-opening decomposition stage (2nd decomposition stage). According to Flynn-Wall-Ozawa method, the average apparent activation energies (Ea) of 1st and 2nd decomposition stages are 257.09 kJ/mol and 117.62 kJ/mol, respectively. The result shows that the de-tert-butylation decomposition stage is more difficult compared with the ring-opening decomposition in the process of PTB-C4 decomposition.