title: Achieving high dielectric constant and low loss property in a dipolar glass polymer containing strongly dipolar and small-sized sulfone groups.
abstract: In this report, a dipolar glass polymer, poly(2-(methylsulfonyl)ethyl methacrylate) (PMSEMA), was synthesized by free radical polymerization of the corresponding methacrylate monomer. Due to the large dipole moment (4.25 D) and small size of the side-chain sulfone groups, PMSEMA exhibited a strong γ transition at a temperature as low as -110 °C at 1 Hz, about 220 °C below its glass transition temperature around 109 °C. Because of this strong γ dipole relaxation, the glassy PMSEMA sample exhibited a high dielectric constant of 11.4 and a low dissipation factor (tan δ) of 0.02 at 25 °C and 1 Hz. From an electric displacement-electric field (D-E) loop study, PMSEMA demonstrated a high discharge energy density of 4.54 J/cm(3) at 283 MV/m, nearly 3 times that of an analogue polymer, poly(methyl methacrylate) (PMMA). However, the hysteresis loss was only 1/3-1/2 of that for PMMA. This study suggests that dipolar glass polymers with large dipole moments and small-sized dipolar side groups are promising candidates for high energy density and low loss dielectric applications.
authors.affiliation: Institute of Microelectronics and Solid State Electronics, University of Electronic Science and Technology of China , Chengdu, Sichuan, P. R. China.
authors.forename: Junji
authors.initials: J
authors.lastname: Wei
authors.forename: Zhongbo
authors.initials: Z
authors.lastname: Zhang
authors.forename: Jung-Kai
authors.initials: JK
authors.lastname: Tseng
authors.forename: Imre
authors.initials: I
authors.lastname: Treufeld
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Liu
authors.forename: Morton H
authors.initials: MH
authors.lastname: Litt
authors.forename: Lei
authors.initials: L
authors.lastname: Zhu
keywords: broadband dielectric spectroscopy; dielectric constant; dipolar glass polymer; electric energy storge; orientational polarization; sub-Tg transition