Eutectic mixtures as a green alternative for efficient catalyst recycling in atom transfer radical polymerizations

Abstract

A new solvent mixture, based on ethanol/reline (EM: eutectic mixture), was investigated for the supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) of methyl acrylate (MA) near room temperature, for the first time, affording complete catalyst recovery and reuse. The kinetic results revealed that the polymerizations were controlled, with polymers having narrow molecular weight distributions ( -D < 1.2). The "living" character of the resultant PMA was confirmed by the synthesis of a welldefined PMA-b-PBA block copolymer. Remarkably, it was demonstrated that the Cu(0)/CuBr 2 /Me 6 TREN (Me 6 TREN: tris[2-(dimethylamino)ethyl]amine) could be recovered from the final reaction mixture and reused for new successful SARA ATRP of MA, suggesting that the reported system could be very attractive from both the economic and environmental perspectives.

Polymer Science and Engineering Using Deep Eutectic Solvents

“…In turn, Maximiano and coworkers published the first article reporting the use of DES as cosolvent in ethanol for supplemental activator and reducing agent atom transfer radical polymerization (SARA ATPR) [76]. Following this new development, Wang et al and Mendonça et al published the first studies on the use of different DES as ligand [77], as 100% solvent for SARA ATPR [78] or both [77].…”

Greener, Faster, Stronger: The Benefits of Deep Eutectic Solvents in Polymer and Materials Science

“…Despite this, there are only a limited number of reports to date where RDRP has been performed in DES systems. The first demonstrations of RDRP in a DES were from the group of Coelho [ 73 , 74 ], who reported the supplemental activator and reducing agent (SARA) ATRP of various acrylates and methacrylates. Their first report detailed the SARA ATRP of MA using reline (a 2:1 urea:ChCl DES) as a co-solvent—the solvent was 90% v / v ethanol (10% v / v reline) due to the immiscibility of MA with reline.…”

Deep Eutectic Solvents in The Synthesis of Polymers

“…Bednarz et al [26], described the free radical copolymerization of itaconic acid−forming DES with ChCl−and AAm by in situ polymerization-crosslinking of the DES (Figure 5). Itaconic acid is a bio-based monomer containing an unsaturated moiety that slowly polymerizes by free radicals; it also has two carboxylic groups available as HBDs [27]. As result of Itaconic Acid (IA) transformation into DES, copolymerization initiated by persulfate proceeded faster and at lower temperature than in water and produced higher crosslinked hydrogels, pointing to a catalytic effect of ChCl.…”