title: Rationally designed polyimides for high-energy density capacitor applications.
abstract: Development of new dielectric materials is of great importance for a wide range of applications for modern electronics and electrical power systems. The state-of-the-art polymer dielectric is a biaxially oriented polypropylene (BOPP) film having a maximal energy density of 5 J/cm(3) and a high breakdown field of 700 MV/m, but with a limited dielectric constant (∼2.2) and a reduced breakdown strength above 85 °C. Great effort has been put into exploring other materials to fulfill the demand of continuous miniaturization and improved functionality. In this work, a series of polyimides were investigated as potential polymer materials for this application. Polyimide with high dielectric constants of up to 7.8 that exhibits low dissipation factors (<1%) and high energy density around 15 J/cm(3), which is 3 times that of BOPP, was prepared. Our syntheses were guided by high-throughput density functional theory calculations for rational design in terms of a high dielectric constant and band gap. Correlations of experimental and theoretical results through judicious variations of polyimide structures allowed for a clear demonstration of the relationship between chemical functionalities and dielectric properties.
authors.affiliation: Polymer Program, University of Connecticut , 97 North Eagleville Road, Storrs, Connecticut 06269, United States.
authors.forename: Rui
authors.initials: R
authors.lastname: Ma
authors.forename: Aaron F
authors.initials: AF
authors.lastname: Baldwin
authors.forename: Chenchen
authors.initials: C
authors.lastname: Wang
authors.forename: Ido
authors.initials: I
authors.lastname: Offenbach
authors.forename: Mukerrem
authors.initials: M
authors.lastname: Cakmak
authors.forename: Rampi
authors.initials: R
authors.lastname: Ramprasad
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Sotzing