SET-LRP of the Hydrophobic Biobased Menthyl Acrylate

Biomacromolecules. 2018 Apr 9;19(4):1256-1268. doi: 10.1021/acs.biomac.8b00090. Epub 2018 Mar 13.

Abstract

Cu(0) wire-catalyzed single electron transfer-living radical polymerization (SET-LRP) of (-)-menthyl acrylate, a biobased hydrophobic monomer, was investigated at 25 °C in ethanol, isopropanol, ethyl lactate, 2,2,2-trifluoroethanol (TFE), and 2,2,3,3-tetrafluoropropanol (TFP). All solvents are known to promote, in the presence of N ligands, the mechanistically required self-regulated disproportionation of Cu(I)Br into Cu(0) and Cu(II)Br2. Both fluorinated alcohols brought out their characteristics of universal SET-LRP solvents and showed the proper polarity balance to mediate an efficient polymerization of this bulky and hydrophobic monomer. Together with the secondary alkyl halide initiator, methyl 2-bromopropionate (MBP), and the tris(2-dimethylaminoethyl)amine (Me6-TREN) ligand, TFE and TPF mediated an efficient SET-LRP of MnA at room temperature that proceeds through a self-generated biphasic system. The results presented here demonstrate that Cu(0) wire-catalyzed SET-LRP can be used to target polyMnA with different block lengths and narrow molecular weight distribution at room temperature. Indeed, the use of a combination of techniques that include GPC, 1H NMR, MALDI-TOF MS performed before and after thioetherification of bromine terminus via "thio-bromo" click chemistry, and in situ reinitiation copolymerization experiments supports the near perfect chain end functionality of the synthesized biobased hydrophobic polymers. These results expand the possibilities of SET-LRP into the area of renewable resources where hydrophobic compounds are widespread.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 2-Propanol / chemistry
  • Acrylates / chemistry
  • Bromine / chemistry
  • Catalysis*
  • Copper / chemistry*
  • Electron Transport
  • Ethanol / chemistry
  • Hydrophobic and Hydrophilic Interactions
  • Lactates / chemistry
  • Ligands
  • Polymerization*
  • Trifluoroethanol / chemistry

Substances

  • Acrylates
  • Lactates
  • Ligands
  • Ethanol
  • Trifluoroethanol
  • Copper
  • ethyl lactate
  • 2-Propanol
  • Bromine
  • cupric oxide
  • methyl acrylate