Thermal decomposition kinetics of calix[a]arene (C4) was investigated using thermogravimetric analysis (TGA) and derivative of TG curve (DIG). TG experiments were carried out under static air atmosphere with nominal heating rates of 1.0, 2.5, 5.0 and 10.0 K/min. Model-fitting methods and model-free methods such as Friedman and Ozawa-Flynn-Wall methods were employed to evaluate the kinetic parameters such as activation energy (E-a), exponential factor (In A) and reaction order (n). To determine the antioxidant property of C4 the non-isothermal kinetics of polypropylene (PP) with C4 as additive was studied. The FTIR, ESR and C-13 NMR CP-MAS techniques were used to propose the decomposition mechanism of C4 in the presence of PP. (C) 2010 Elsevier B.V. All rights reserved.