FT-IR and FT-Raman spectroscopy study of di-urethanesil hybrids doped with Mg(CF 3SO 3) 2

Abstract

In the present work di-urethane cross-linked poly(oxyethylene) (POE)/siloxane hybrids (di-urethanesils) incorporating magnesium triflate (Mg(CF 3SO 3) 2) with 100 ≥ n ≥ 2 (where n, composition, is the molar ratio of oxyethylene repeat units per Mg 2+ ion) have been characterized by Fourier transform infrared and Raman spectroscopy to elucidate the Mg 2+/POE, Mg 2+/urethane, Mg 2+/CF 3SO 3 − and hydrogen bonding interactions. The Mg 2+ ions bond to POE chains and to the carbonyl oxygen atoms of the urethane linkages over the whole range of salt content studied. A crystalline POE/Mg(CF 3SO 3) 2 complex of unknown stoichiometry is formed at n = 5. “Free” and weakly coordinated CF 3SO 3 − ions are present in all the materials examined. Contact ion pairs emerge at n ≤ 20 and higher ionic aggregates appear at n ≤ 5.