Homogeneous and blended ER fluids with polyether derivatives

Various ER fluids were prepared based on polyethers such as polypropylene g lycol and polytetramethylene glycol. The polyethers were modified with isoc yanates to give homogeneous liquids which show a positive or a negative ER effect depending on the molecular structure. The molecular motion of an ure a-derivative of the polyether was analyzed with the NMR relaxation method. The modified polyethers were also used as a component of immiscible blends with silicones and suspensions. The immiscible blends showed a positive ER effects even when the polyether showed a negative ER effect. The suspension s tended to show a positive ER effect, which is similar to usual ER suspens ions.