Study on an electrorheological effect of side-chain polysiloxanes including fluorine atoms by the preshearing method

Side-chain liquid-crystalline polysiloxane derivatives possessing fluorinated mesogens that have positive dielectric-anisotropy parallel to the long axis of meso-gen were synthesized to study phase-transition behavior and electrorheological (ER) effect of the polymers with a preshearing method. About 2000 Pa increments in shear stress could be obtained after preshearing as an ER effect. In addition, shear rate dependence on shear stress as a function of temperature was investigated. As a result, it was shown that the preshearing treatment with high shear rate was important to generate a larger ER effect.