Dielectric Properties of C₆₀ and Sc₃N@C₈₀ Fullerenol Containing Polyurethane Nanocomposites

Authors

Hanaa M. Ahmed, University of Southern MississippiFollow
Mohammad K. Hassan, University of Southern MississippiFollow
Kenneth A. Mauritz, University of Southern MississippiFollow
Steven L. Bunkley, University of Southern Mississippi, School of ComputingFollow
Randy K. Buchanan, University of Southern Mississippi, School of Computing
J. Paige Buchanan, University of Southern MississippiFollow

Document Type

Article

Publication Date

8-5-2014

Department

Chemistry and Biochemistry

School

Mathematics and Natural Sciences

Abstract

Polymer–fullerene nanocomposites consisting of linear polyurethane (PU) chains crosslinked via increasing loadings of polyhydroxylated fullerenes (C₆₀ and Sc₃N@C₈₀, a metallic nitride fullerene) were prepared and characterized for their mechanical and dielectric properties using dynamic mechanical analysis (DMA) and broadband dielectric spectroscopy (BDS). Fullerene–polymer networks [C₆₀-PU and Sc₃N@C₈₀-PU] having high gel fractions, good mechanical properties and thermal stabilities were produced. Polyhydroxylated fullerenes C₆₀(OH)₂₉ and Sc₃N@C₈₀(OH)₁₈ were synthesized in high yield through a high-speed vibration milling method and characterized using FTIR, matrix-assisted laser desorption/ionization mass spectroscopy, and thermal gravimetric analysis. DMA of fullerene–PU networks indicates T_g ∼ −50°C, with a sub-T_g relaxation due to local chain motions. BDS analyses of the fullerenes, before and after hydroxylation and before incorporation into the networks, revealed one relaxation and large real permittivity (ε′) values for C₆₀(OH)₂₉ relative to C₆₀. Analogous samples for Sc₃N@C₈₀ exhibit two relaxations, where the extra relaxation is attributed to motions of the cage-encapsulated Sc₃N clusters. ε′ values for Sc₃N@C₈₀-PU at a given frequency are higher than corresponding values for C₆₀-PU, likely because of the rotationally mobile Sc₃N encapsulates. Surface and bulk resistivities of fullerene–PU networks were found to have a modest dependence on relative humidity. Capacitance versus voltage characteristics of the fullerene–PUs were also studied in the range of the applied dc bias voltage of −30 to +30 v. It is generally concluded, based on all the evidence that this class of materials can be rendered quite polarizable and could be used as high dielectric permittivity materials in capacitance applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40577.

Publication Title

Journal of Applied Polymer Science

Volume

131

Issue

15

Recommended Citation

Ahmed, H., Hassan, M., Mauritz, K., Bunkley, S., Buchanan, R., Buchanan, J. (2014). Dielectric Properties of C₆₀ and Sc₃N@C₈₀ Fullerenol Containing Polyurethane Nanocomposites. Journal of Applied Polymer Science, 131(15).
Available at: https://aquila.usm.edu/fac_pubs/19904