Dielectric Properties of Addition Poly(5-n-alkylnorbornenes)

Dielectric properties of a series of addition poly(5-n-alkylnorbornenes) (alkyl = ethyl, n-butyl, n-hexyl, n-decyl, and n-tetradecyl) were studied in a wide range of electric field frequencies (0.01–1 × 10⁶ Hz) and temperatures (form –100 to +100°С). The relative dielectric permittivity of these polymers varies from 1.97 to 2.31 at the field frequency of 1 MHz and temperature of 25°С. Addition poly(5-n-butyl-2-norbornene) has the minimal dielectric permittivity. The dielectric permittivity of the addition polymers in the glassy state remained virtually constant in the frequency and temperature ranges examined. All the polynorbornenes prepared exhibit low values of the dielectric loss (εʺ ~ 10^–3–10^–4) and dielectric loss tangent (tan δ ~ 10^–3–10^–4) in the major part of the frequency and temperature ranges examined. However, εʺ and tan δ of the polymers with long alkyl substituents (n-hexyl, n-decyl, and n-tetradecyl) considerably increased at low frequencies and high temperatures.