On the Precipitation Copolymerization of 1‐Octene and Glycidyl Methacrylate in Supercritical Carbon Dioxide

The free radical precipitation copolymerization of the polar monomer glycidyl methacrylate (GMA) and the nonpolar monomer 1-octene (Oct) in supercritical carbon dioxide (sc-CO2) is reported under different conditions of pressure and temperature. According to H-1 NMR studies, in the obtained statistical copolymers (GMA-stat-Oct) the molar fraction of the olefin (F-Oct) increases when the pressure and temperature of the reaction increased from the reference values T = 125 degrees C and P = 34 bar. In particular, when the initial molar fraction of Oct (f(Oct)) is 0.83, the molar fraction of this monomer in the final copolymer reaches a maximum value of 0.22 at 124 bar and T = 155 degrees C. On the other hand, for f(Oct) = 0.89, it is obtained that F-Oct = 0.25 at 124 bar and T = 155 degrees C. Copolymers obtained are characterized by NMR, scanning electron microscopy, and size exclusion chromatography techniques. Finally, two copolymers were selected to demonstrate the feasibility of modifying the GMA moiety in order to introduce OH polar groups giving rise to Oct-stat-glycerol methacrylate copolymers.