TG/DSC/FTIR/QMS analysis of environmentally friendly poly(citronellyl methacrylate)-co-poly(benzyl methacrylate) copolymers

Abstract

Polymer materials, not described in the literature so far, were obtained in the process of UV polymerization between methacrylic monomer obtained on the basis of natural, terpene alcohol: citronellyl methacrylate and benzyl methacrylate with different composition. The structures of the novel, environmentally friendly copolymers were confirmed by the FTIR and 13C CPMAS/NMR spectra. The copolymers containing more than 50% mass of citronellyl methacrylate were characterized by a high conversion of the double bonds determined on the basis of the FTIR and NMR spectra (95–96% and 92–94%, respectively). The novel materials were highly resistant to polar and non-polar solvents and the chemical stability. The glass transition temperature was from 15.8 to 19.9 °C which confirms that the obtained materials are elastomers at room temperature. Their thermal stability depended on their composition. It was from 185 to 205 °C (inert conditions) and from 149 to 214 °C (oxidizing conditions). TG/FTIR/QMS studies confirmed that their decomposition took place mainly as a depolymerization process combined with a subsequent breaking of the bonds in the resulting monomer/s at higher temperatures, which led to the formation of the gases with lower molecular masses. The main decomposition products emitted in an inert atmosphere were benzyl methacrylate, citronellyl methacrylate, 2-methylpropenal, citronellal and higher molecular mass compounds formed as a result of radical reactions between intermediate volatile products. In turn, under oxidizing conditions, as volatiles, benzyl methacrylate, citronellyl methacrylate, 2-methylpropenal, citronellal and small amounts of inorganic gases (CO, CO2, H2O) as a result of depolymerization and some combustion processes of the residues were indicated.