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*Chemical Engineering Department, Kuwait University, P.O. Box 5969, 13060 Safat, Kuwait Email: adamalmulla@kuc01.kuniv.edu.kw

ABSTRACT

The kinetics of the thermal degradation of poly(ethylene terephthalate) (PET), poly(methyl methacrylate) (PMMA) and four different blends of PET and PMMA (PET90/PMMA10, PET75/PMMA25, PET50/PMMA50 and PET25/PMMA75 weight/weight percent), developed using a batch mixing process, were investigated by Thermogravimetric Analysis (TGA). Kissinger, Friedman, Park-Oh-Lee-Kim-Yo, Vyazovkin and Ozawa models have been used to characterize the degradation kinetics of the polymers under study at the heating rates 5, 10, 15 and 20⁰ C/min under nitrogen atmosphere. The kinetic parameters evaluated were the activation energy(E_a) Arrhenius pre-exponential factor (A) and degradation reaction order (n). The fitting of each model to the experimental data was evaluated using the correlation coefficient (r). The results indicated that Park-co. and Kissinger models gave similar values of E_a and Ln (A), while those obtained using Vyazovkin and Ozawa were almost identical. PET/PMMA blends in general exhibited higher activation energies, and thus better thermal stabilities, than PMMA.