Hamid Reza Azimi - Institute of Polymeric Materials, Chemical Engineering Department, Sahand University of Technology
Mostafa Rezaei - Institute of Polymeric Materials, Chemical Engineering Department, Sahand University of Technology
Farhang Abbasi - Institute of Polymeric Materials, Chemical Engineering Department, Sahand University of Technology
Yahya Bahluli - Metallurgical Research Center, Iran Tractor Foundry Company, Tabriz

Methylmethacrylate-styrene (MMA-St) random copolymer was synthesized by suspension copolymerization. The thermal degradation of MMA-St copolymer and EPS lost foams was studied by non-isothermal thermal gravimetric analysis under nitrogen purge. It was found that EPS foam starts to decompose at higher temperatures than MMA-St copolymer foam in all heating rates. The apparent activation energy was calculated by the Flynn-Wall-Ozawa method. It has been concluded that the model fitting methods is unable to reveal the complexity of the pyrolysis process and the model-free methods can be suggested as a reliable way of determining the kinetic parameters. In this work the isokinetic relationship (IKR) was used to estimate a model-independent pre-exponential factor (lnA) corresponding to a given degree of conversion.

Lost foam, MMA-St copolymer, EPS, Degradation kinetics, IKR