Green production of ion-conductive and self-healable polymers by photoinduced radical polymerization of ternary deep eutectic monomers

Abstract

We developed ternary deep eutectic monomers (DEMs) for the green production of ion-conductive and self-healable polymeric deep eutectics by photoinduced radical polymerization. The liquid DEMs were prepared by mixing three solids: N-isopropyl acrylamide (NIPAM) as an amido-containing monomer, N-isopropylpropionamide (NIPPA), and metal salts (lithium bis(trifluoromethanesulfonyl)imide and zinc chloride). The photopolymerization of NIPAM/NIPPA/metal salt DEMs afforded polymeric deep eutectics with tunable flexibility and ion-conductive and self-healing properties. The NIPAM/NIPPA/metal salt feed ratios and the nature of the metal salts substantially influenced the unique features of the DEMs and the properties of the poly(DEM)s. These polymeric eutectics consisting of the NIPAM-based ternary DEMs not only provide a practical and efficient method for the preparation of ion-conductive and self-healable polymers, but also allow green radical polymerization (almost 100% atom economy without using any volatile organic solvents in both the monomer synthesis and polymerization, and ultrafast polymerization under ambient conditions).