Microwave‐Assisted Homogeneous Polymerizations in Water‐Soluble Ionic Liquids: An Alternative and Green Approach for Polymer Synthesis

Abstract

Water‐soluble ionic liquids (IL) were used as reaction media to perform homogeneous polymerizations under microwave irradiation. The investigated reaction systems include the free radical polymerization of methyl methacrylate and the cationic ring opening polymerizations of 2‐phenyl‐2‐oxazoline and 2‐(m‐difluorophenyl)‐2‐oxazoline. The incorporation of ILs into the polymerizations showed a more efficient heating profile of the reaction mixtures under microwave irradiation in comparison to the cases without ILs. Moreover, a convenient approach for the polymer isolation and recovery of the ILs for further polymerizations is demonstrated taking advantage of the water solubility of the investigated ILs. This synthetic approach is an alternative, efficient, and green method for the manufacture of hydrophobic polymers which may allow depletion of the emission of volatile organic compounds into the environment and for energy savings.

Synthesis and processing of biodegradable and bio-based polymers by microwave irradiation

“…3), carbon black (F. or silica particles (P. Liu & Su, 2005). Microwave assisted reactions may also be conducted in environmentally friendly water-miscible ionic liquids which are characterized by high dielectric constants and offer the possibility of isolating hydrophobic products by the addition of water to the homogeneous solution (Guerrero-Sanchez et al, 2007). When possible, the solvent-free option should always be favored on the basis of the green chemistry principles: the bulk ring opening polymerization of lactide to yield poly(lactic acid) is a notable case (Frediani et al, 2010).…”

One Decade of Microwave‐Assisted Polymerizations: Quo vadis?

“…Schubert and coworkers compared the microwaveassisted bulk polymerization of MMA in two different water soluble ionic liquids, namely 1-butyl-3-methylimidazolium trifluoromethane-sulfonate (IL1) and 1-butyl-3-methylimidazolium tetrafluoroborate (IL2), in the single mode microwave reactor Biotage Emrys Liberator. [17] Ionic liquids, one of the current key strategies to replace volatile organic compounds, were chosen as medium for energyefficient, solvent-free polymerization processes. The monomers were soluble in both ionic liquids, while the polymer was only soluble in IL1.…”

Micellar dye shuttle between water and an ionic liquid

“…Recently the utilization of ionic liquids (ILs) as new solvents [1][2][3][4][5][6][7][8][9] for the preparation of self-assembled nanostructures (micelles) formed by amphiphilic block copolymers has triggered attractive new possibilities for the design of advanced and ''smart'' polymer based physico-chemical systems. [10][11][12][13][14][15][16][17][18][19][20][21] Interestingly, the thermoreversible transfer of block copolymer micelles and nanocarriers between a hydrophobic IL phase and an aqueous phase was recently demonstrated based on the decreased solubility of the hydrophilic block in aqueous solution with increasing temperature.…”