Thermal degradation of poly 2-[3-(6-tetralino)-3-methylcyclobutyl]-2-ketoethyl methacrylate

Abstract

The thermal degradation of poly 2-[3-(6-tetralino)-3-methyleyelobutyl]-2-ketoethyl methacrylate [poly(TKEMA)] 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). The 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 degreesC/min from room temperature to 500 degreesC. In degradation of [poly(TKEMA)], product identification studies were done using FT-IR, H-1 and C-13 NMR and gas chromatography-mass spectroscopy. Depolymerization is the main reaction in thermal degradation of the polymer. The degradation produces anhydride ring structures in the chain at temperatures up to about 300 degreesC. The cleaving of ketone, aldehyde, tetralin compounds from side chains of the polymers is a common reaction for the polymers. A mechanism of degradation showing the formation of some of these products is discussed. The activation energy for the thermal degradation of [poly(TKEMA)] is 210 kJ/mol in the first stage, observed at 220-330 degreesC. The second stage decomposition commenced at 330-430 degreesC and the energy of activation was 125 kJ/mol. (C) 2003 Elsevier Science Ltd. All rights reserved.