Mehrdad Seifali Abbas-Abadi - Polymerization Engineering, Iran Polymer and Petrochemical Institute (IPPI), Tehran, Iran
Mehdi Nekoomanesh Haghighi - Polymerization Engineering, Iran Polymer and Petrochemical Institute (IPPI), Tehran, Iran
Hamid Yeganeh - Polymerization Engineering, Iran Polymer and Petrochemical Institute (IPPI), Tehran, Iran

Polyethylene (PE) is the largest synthetic commodity polymer in terms of annual production and is widely used throughout the world due to their versatile physical and chemical properties [1]. The thermal pyrolysis of PP and PE is known to follow the random chain scission route, resulting in mainly oligomers and dimers although chain stripping and crosslinking mechanism can affect the polyethylene degradation. Thermogravimetric analysis (TGA) is a common method forstudying the kinetics of polymer degradations. Kinetic analysis may effectively assist in the probing of degradationmechanisms and in the prediction of the thermal stability of polymers especially in PE [3-5]. The purpose of this work is to study the degradation behaviors of different grades of thepolyethylenes using TGA by Friedman method for determining the kinetic parameters.