Kinetic Analysis of the Thermal Decomposition of Latex Foam according to Thermogravimetric Analysis

Abstract

The thermal decomposition of latex foam was investigated under nonisothermal conditions. Pieces of commercial mattress samples were subjected to thermogravimetric analysis (TG) over a heating range from 5°C min −1 to 20°C min −1 . The morphology of the latex foam before and after combustion was observed by scanning electron microscopy (SEM), and the primary chemical composition was investigated via infrared spectroscopy (FT-IR). The kinetic mechanism and relevant parameters were calculated. Results indicate that the decomposition of latex foam in the three major degradation phases is controlled by third-order reaction (F3) and by Zhuravlev’s diffusion equation (D5). The mean <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>E</mml:mi></mml:mrow></mml:math> values of each phase as calculated according to a single heating rate nonisothermal method are equal to 41.91 ± 0.06 kJ mol −1 , 86.32 ± 1.04 kJ mol −1 , and 19.53 ± 0.11 kJ mol −1 , respectively. Correspondingly, the preexponential factors of each phase are equal to 300.39 s −1 , 2355.65 s −1 , and 27.90 s −1 , respectively. The mean activation energy <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>E</mml:mi></mml:mrow></mml:math> and preexponential factor <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:mi>A</mml:mi></mml:mrow></mml:math> of latex foam estimated according to multiple heating rates and a nonisothermal method are 92.82 kJ mol −1 and 1.12 × 10 −3 s −1 , respectively.