Electric breakdown strength of aromatic polymers: dependence on film thickness and chemical structure

The AC electric breakdown field strength F_B of aromatic polymer films as a function of sample thickness was investigated. A power-law dependence of F_B on sample thickness was found. The exponential parameter of the power law was shown to correlate with the electron accepting properties of the polymer. Reasonable values of the electron accepting properties of the polymers were assigned through the determination of the reversible electrochemical reduction potentials E_rev of suitable model compounds. A good correlation between the exponential factor of the power law and E_rev was obtained. The physical meaning of the parameters in the power law is discussed in terms of the chemical structure of the polymers and their ease of ionization