Conductivity and dielectric properties of heterogeneous films based on homo- and copolymers of methyl (methacrylate) and vinyl pyrrolidone doped with ionic liquid

• Published in: European polymer journal 2014-10, Vol.59, p.247-253
• Main Authors: Grishina, E.P., Ramenskaya, L.M., Mudrov, A.N.
• Format: Article
• Language: English
• Subjects: Acetone; Chloroform; Conductivity; Copolymers; Dielectric constant; Dielectric properties; Droplets; Heterogeneous polymer films; Ionic liquid; Ionic liquids; Polymethyl methacrylates; Solvents
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2014.07.041

[Display omitted] •Macro and micro phase separation polymer/ionic liquid films were prepared.•Conductivity, percolation threshold and dielectric characteristics were estimated.•The exponential concentration depending of ionic conductivity was found.•A size droplet of ionic liquid has a significant influence on conductivity. Poly(methyl methacrylate) (PMMA), poly(methyl methacrylate-co-vinyl pyrrolidone) (PMMA-co-VP) and ionic liquid of 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6) have been used to prepare the micro or macro heterogeneous polymer films by a solution casting method in acetone and chloroform as solvents. The resulted films were studied by means of the alternating current conductometry and optical microscopy methods. The frequency dependences of specific volume conductivity, dielectric constant and tangent loss were obtained. The influence of a polymer matrix and solvent nature on ionic conductivity was analyzed. For PMMA/BMIPF6 formed in chloroform as macro heterogeneous film, a higher conductivity of 0.6×10−5S/cm (25°C) was achieved. The conductivity of phase separated heterogeneous polymer/ionic liquid films was proposed to depend on a size of ionic liquid droplets captured by polymer matrix.