Previous Issues
Volume :36 Issue : 2 2009
Add To Cart
Download
Blends of poly(ethylene Terephthalate) and poly (methyl methacrylate): II. Non-isothermal degradation kinetics
Auther : ADAM AL-MULLA*, SAMI H. ALI AND MISHAL AL-HASSAN
*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(Ea) 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 Ea 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.