ELECTROVISCOELASTIC EFFECT OF POLYMER BLENDS CONSISTING OF SILICONE ELASTOMER AND SEMICONDUCTING POLYMER PARTICLES

Dynamic viscoelasticity of immiscible polymer blends consisting of silicone elastomer and semiconducting polymer particles was studied under the influence of electric fields. The semiconducting polymers used experimentally were poly(p-phenylenes) lightly doped with CuCl2 or FeCl3. The dc electric fields enhanced storage and loss shear moduli of the polymer blends (electroviscoelastic effect). The ac electric fields with frequencies of less than 1 kHz also induced the electroviscoelastic effect. The electroviscoelastic effect was observed in the rubbery state of the blends with many lines of adjacent particles spanning the space between electrodes. The electroviscoelastic behavior for the polymer blends with straight lines of adjacent particles aligned to electric fields was analyzed using a point-dipole approximation model for electrically polarized particles. The presented results provide insight into the relationship between mechanical properties of the blends and the cohesive forces between electrically polarized particles.