Effect of room-temperature ionic liquids as replacements for volatile organic solvents in free-radical polymerization

Room temperature ionic liquids (RTILs) are a class of solvents that can be used in polymer synthesis to replace volatile organic compounds. However, to make the transition of ionic liquids from laboratory scale to industrial scale, the reactions must be feasible, they must produce polymers that have similar or better mechanical properties to traditional methods, and the ionic liquids must be recyclable. Polystyrene, poly(methyl methacrylate), and poly(2-hydroxyethyl methacrylate) were made by bulk and solution polymerization using both traditional organic solvents and ionic liquids. The monomer and polymer solubilities were tested in the ionic liquids, and physical properties, including the tensile moduli and glass transition temperatures, were measured. Results are encouraging, in that the tensile moduli are not statistically different whether the polymer was formed in organic solvent or in ionic liquid solvent.