Synthesis of pyrrolidinium-based poly(ionic liquid) electrolytes with poly(ethylene glycol) side-chains

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1 Supporting information Synthesis of pyrrolidinium-based poly(ionic liquid) electrolytes with poly(ethylene glycol) side-chains Markus Döbbelin, a,* Itxaso Azcune, a Mélanie Bedu, b Alaitz Ruiz de Luzuriaga, a Aratz Genua, a Vasko Jovanovski, a,c Germán Cabañero a and Ibon Odriozola a,* a New Materials Department, CIDETEC, Center for Electrochemical Technologies, Parque Tecnológico de San Sebastián, Paseo Miramón 196, Donostia-San Sebastián 20009, Spain b SOLVIONIC, Chemin de la loge, CS 27813, Toulouse Cedex 4, France c Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia * mdobbelin@cidetec.es; iodriozola@cidetec.es S-1

2 Contents Reaction conditions for the polymerization of PEG functionalized monomers... 3 MALDI-TOF analysis C NMR of functionalized polymers... 5 References... 7 S-2

3 Reaction conditions for the polymerization of PEG functionalized monomers Monomers based on diallyl methyl amine with PEG groups with one, two and three ethylene oxide units were prepared. Therefore, diallyl methyl amine hydrochloride (1 equiv.) was dissolved in a minimum amount of methanol, just to dissolve the chemical, and placed in an ice bath. Subsequently, sodium methoxide (1 equiv.), also dissolved in a minimum amount of methanol, was added. The reaction was stored in a freezer for 1h and NaCl was filtered off. To the neutralized diallyl methyl amine (1 equiv.) methanol solution, toluene (it was found that the reaction yields increased from 40% to over 90% when toluene was added) and the alkyl iodides (1.2 equiv.) were added and the reaction mixtures were vigorously stirred at room temperature for 48 h. The formed iodide monomeric ionic liquids were insoluble in toluene and could be separated by decantation. The monomeric ionic liquids were washed with diethylether (3x) and solvents were removed on the rotary evaporator. Scheme 1S shows the synthesis scheme of the monomeric ionic liquids with pendant PEG side chains. Scheme 1S. Synthesis scheme of the monomeric ionic liquids with pendant PEG side chains. Different reaction conditions were applied in order to polymerize the three obtained monomeric ionic liquids: 1) The iodide monomeric ionic liquids with pendant PEG chains (one, two and three ethylene oxide units, respectively) (1 equiv.) were dissolved in water and purged with nitrogen for 20 min. The initiator 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH, 0.03 equiv.) was added and the mixtures were purged for another 5 min. The reactions were stirred under nitrogen atmosphere at 60 C for 72 h. Water was removed by freeze-drying. 1 H NMR did not confirm polymerization. 2) The reactions were repeated using chloroform as solvent and azo-bis-(isobutyronitril) AIBN (0.03 equiv.) as initiator. The other reaction conditions were the same. 1 H NMR did not confirm polymerization. S-3

4 3) The reactions were repeated using acetone as solvent and AIBN (0.03 equiv.) as initiator. The other reaction conditions were the same. 1 H-NMR did not confirm polymerization. 4) The iodide anions of the monomer ionic liquids were replaced by bis(trifluoromethane)sulfonimide (TFSI) anions (for the anion exchange the same procedure was used as for the preparation of the ionic liquids IL1-IL4) and the reactions were carried using acetone as solvent and AIBN (0.03 equiv.) as initiator. The other reaction conditions were the same. 1 H-NMR did not confirm polymerization. 5) The reactions (1-4) were repeated using higher amounts of initiator AAPH/AIBN (0.1 equiv. with respect to the monomers). 1 H-NMR did not confirm polymerization. MALDI-TOF analysis Maldi-Tof analysis were performed on a Bruker Microflex, operated in positive linear mode using indoleacrylic acid (20 mg/ml) in THF as a matrix. Figure 1S shows the Maldi-Tof analysis of poly(diallyl methyl amine) for which a molecular weight of ca g/mol was detected. It is noted, that the obtained molecular weight is an approximate value as the accurate determination of the molar-mass distributions depends on the polydispersity. An accurate molar-mass distributions can be obtained for polymers with a low polydispersity. For polymers with a higher polydipsersity (typically greater than 1.2) variations in the molecular weight have to be considered. 1,2 Figure 1S. Maldi-Tof of poly(diallyl methyl amine). S-4

5 13 C NMR of functionalized polymers As in the 1 H NMR spectra, a splitting in the 13 C NMR spectra indicates the presence of stereoisomers. Splitting has been reported previously for free radical and RAFT polymerized poly(diallyldimethyl)ammonium-based polymers. 3,4 Figure 2S shows the 13 C NMR spectra of the functionalized polymers (PIL1-PIL4). S-5

6 Figure 2S. 13 C spectra of PILs with pendant PEG chains. S-6

7 References (1) Axelsson, J.; Scrivener, E.; Haddleton, D. M.; Derrick, P. J. Macromolecules 1996, 29, (2) Rashidzadeh, H.; Guo, B. Anal. Chem. 1998, 70, (3) Assem, Y.; Chaffey-Millar, H.; Barner-Kowollik, C.; Wegner, G.; Agarwal, S. Macromolecules 2007, 40, (4) Tirelli, N.; Hunkeler, D. J. Macromol. Chem. Phys. 1999, 200, S-7