Copolymers of glycidyl methacrylate and octadecyl acrylate: synthesis, characterization, swelling properties, and reactivity ratios

The free radical copolymerization of glycidyl methacrylate (GMA) and octadecyl acrylate (ODA) was carried out at 70 °C in solution using toluene as solvent and 2,2′-azobisisobutyronitrile (AIBN) as initiator. The copolymer compositions were determined using 1H NMR spectroscopy. The monomer reactivity ratios were computed using five linear methods at low conversions, i.e. Mayo–Lewis (ML), Fineman–Ross (FR), inverted Fineman-Ross (IFR), Ezrielev–Brokhina– Roskin (EBR) and Kelen–Tudos (KT). The reactivity ratios resulted from different methods are in agreement with each other and showed higher reactivity for GMA monomer in comparison with ODA monomer (FR: r G = 1.29 and r O = 0.68). Crosslinked GMA–ODA copolymers were also prepared using ethylene glycol dimethacrylate as a crosslinker. Thermal properties and swelling behaviors of crosslinked copolymers in different polar and nonpolar solvents were evaluated. GMA incorporation in the crosslinked copolymers improved T g values, while decreased T m quantities and swelling in nonpolar solvents. The swelling values are in the acceptable range and the prepared functional crosslinked copolymers can be used for nonpolar solvents absorbency applications.