• 文献标题:   Composites prepared from the waterborne polyurethane cationomers-modified graphene. Part II. Electrical properties of the polyurethane films
  • 文献类型:   Article
  • 作  者:   KROL P, KROL B, ZENKER M, SUBOCZ J
  • 作者关键词:   volume resistivity, havriliaknegami equation, dielectric constants epsilon epsilon in frequency domain, dielectric losses coefficient tg delta
  • 出版物名称:   COLLOID POLYMER SCIENCE
  • ISSN:   0303-402X EI 1435-1536
  • 通讯作者地址:   Rzeszow Univ Technol
  • 被引频次:   5
  • DOI:   10.1007/s00396-015-3697-2
  • 出版年:   2015

▎ 摘  要

The research was planned to test electrical properties of polymer films made from polyurethane cationomers with 0-2 wt.% graphene admixture. The cationomers were synthetized in the reaction of 4,4'-methylenebis(phenyl isocyanate), polycaprolactone diol (M = 2000), N-methyldiethanolamine, and formic acid. It was found that addition of approx. 2 wt.% of graphene causes the loss of volume resistivity by three orders of magnitude and percolation threshold is already set at approx. 1 wt.%. The frequency characteristic of a real part of permittivity epsilon' and imaginary part of permittivity epsilon aEuro(3) were measured for the tested films. On the base of Havriliak-Negami equation, parameters of relaxation functions in frequency domain were estimated for samples containing various contents of graphene. The influence of the cationomer phase structure on observed changes of dielectric losses coefficient tg delta in the full-measuring frequency spectrum was discussed.