Kinetic Study of Low Density Polyethylene Using Thermogravimetric Analysis, Part 2: Isothermal Study

Abstract

Thermal behavior of plastic materials can be improved by knowing thermal degradation kinetics for the optimal design and operation of pyrolysis process. In continuity of part 1 of the present study, Thermogravimetric analysis has been used for isothermal kinetic study of waste Low-Density Polyethylene (LDPE) pyrolysis under Argon atmosphere at different temperatures 420, 430, 440, 450, 460 and 470 C. These isotherms were chosen after determining the range of thermal degradation of LDPE using Thermogravimetric analysis in nonisothermal conditions. This work aims to analyze the applicability of simples kinetic models to the prediction of the thermal behavior of the material, taking into account the complex chain reaction mechanism. Because of this complex reaction mechanism, the reaction order of pyrolysis of LDPE was determined. Freidman method has been used to obtain the activation energy and the frequency factor from isothermal experiments and compare them with the values obtained from non-isothermal experiments obtained in part 1 and with the results obtained by other authors.