A novel pre‐shearing technique for measurement of the electrorheological effect of a side‐chain liquid crystalline polysiloxane

A side‐chain liquid crystalline polysiloxane derivative possessing mesogens was synthesized. The mesogens included a large dielectrically‐anisotropic moiety. Phase transition behaviour was investigated and the electrorheological (ER) effect of the polymer considered. No ER effect was observed in non‐sheared polysiloxane derivative because of its high inherent viscosity. However, a large ER effect was observed after pre‐shearing. Pre‐shearing, i.e. shearing with a high shear rate before the measurements, arranges the terminal mesogens in the shearing direction. Furthermore, a dilution of the sample led to a larger ER effect exceeding 10 000 Pa. We thus were able to demonstrate a new approach for the appearance of the ER effect.