PROPERTIES OF ER FLUIDS COMPRISED OF LIQUID CRYSTALLINE POLYMERS

摘要

Side-chain liquid crystalline polysiloxanes (LCS) diluted with solvents show a large increase in viscosity and a newtonian flow under an electric field. Two types of solvent-diluted LCSs, A and B, are presented and their properties are described in this paper. Type A shows a large temperature-dependent ER effect a quick response of msec order to an electric field and a dynamic behavior similar to that of a low molecular weight liquid crystal. Type B shows a stable ER effect throughout a wide range of temperatures up to 150 °C. a two-step response of shear stress curve upon application of DC electric field and a micron-sized droplets structure which deforms with the electric field. The generation mechanisms of ER effect on the two types were discussed with the data of dynamic and morphological changes, referring those on a low molecular liquid crystal and a particle dispersion type ER fluid.