Novel furan compounds, which incorporate phenyl rings separated by alkene spacers, have been synthesized. Chemical polymerization of these compounds yielded black brittle powders, suspensions of which were found to exhibit significant electrorheological (ER) properties, with reversible viscosity increases on application and removal of an external electric field. Electrochemical polymerization of the monomers yielded polymer films that showed an absence of redox properties. Evidence is provided for polymer structures with furan ring opening to give carbonyl links between the monomer units. This paper shows there is considerable scope for further refinement of ER fluids by exploring the versatility of furan chemistry, particularly due to its ease of derivitization at the 3, 4 positions.