Akademik Veri Yönetim Sistemi
Polymer Degradation and Stability, cilt.78, sa.3, ss.497-503, 2002 (SCI-Expanded)
The thermal degradation of poly(phenacyl methacrylate) [poly(PAMA)] has been studied using a system consisting of a degradation tube, with a condenser for product collection, a gas phase IR cell and a rotary pump and by thermogravimetry (TG). Investigation of the nature of the evolved products has been supplemented by studies of structural changes in the degrading polymer by FT-IR spectroscopy. Changes have been investigated under programmed heating at 10 °C/min from room temperature to 500 °C. In degradation of poly(PAMA), product identification studies were done using FT-IR, 1H- and 13C-NMR and gas chromatography-mass spectroscopy techniques. Depolymerization is the main reaction in thermal degradation of the polymer. The degradation produces anhydride ring structures in the chain at temperatures above 300 °C. Total degradation to 430 °C produces many volatile product such as the monomer, acetophenone, benzaldehyde and others. A mechanism of degradation showing the formation of some of these products is discussed. The activation energy for the thermal degradation of poly(PAMA) is 89.2 kJ/mol in the first stage observed at 207-300 °C. The second stage decomposition commenced at 300-430 °C and the energy of activation was 66.9 kJ/mol. © 2002 Elsevier Science Ltd. All rights reserved.