Synthesis, characterization, and thermal degradation of novel poly(2-(5-bromo benzofuran-2-yl)-2-oxoethyl methacrylate)

Abstract

A novel methacrylate monomer containing benzofuran side group, 2-(5-bromo benzofuran-2-yl)-2-oxoethyl methacrylate (BOEMA), was synthesized from esterification reaction of 2-bromo-1-(5-bromo benzofuran-2-yl) ethanone with sodium methacrylate at 85 degrees C in the presence of 1,4-dioxane solvent. After characterization with Fourier transform infrared spectrophotometer, nuclear magnetic resonance (1H-NMR and 13C-NMR), its homopolymerization was carried out by free radical polymerization at 60 degrees C in the presence of benzoyl peroxide initiator and 1,4-dioxane solvent. The glass transition temperature (Tg) of the synthesized novel polymer, poly(2-(5-bromo benzofuran-2-yl)-2-oxoethyl methacrylate) [poly(BOEMA)], was determined to be 137 degrees C with differential scanning calorimetry technique. Thermal degradation kinetics of poly(BOEMA) was investigated by thermogravimetric analysis method at different heating rates with 5 degrees C/min intervals between measurements. From dynamic measurements, the analysis of each process mechanism of CoatsRedfern and Van Krevelen methods showed that the most probable model for the decomposition process of poly(BOEMA) homopolymer agrees with the random nucleation, F1 mechanism. The apparent decomposition activation energies of poly(BOEMA) by Kissinger's and FlynnWallOzawa methods in the studied conversion range were 188.47 and 180.13 kJ/mol, respectively. POLYM. ENG. SCI., 2012. (C) 2011 Society of Plastics Engineers