Synthesis and electrorheological characterization of polymer containing amino and carboxy groups

A new polymer (poly[N,N′-(2-amino-5-carboxy-1,3-phenylenedimethylene)-2,2′-diamino-4,4′-bithiazole], PACPDMDABT) containing amino and carboxy groups was synthesized. This polymer can be used as a disperse phase to prepare excellent electrorheological (ER) fluids. Several ER fluids were prepared (1) with the polymer in different type of disperse mediums (bromodiphenylmethane and silicone oil) and (2) with different polymer concentration in each type of the disperse medium. Rheological properties of the fluids were measured. Impact of the strength of the applied electric field, disperse phase concentration and different disperse mediums to the ER properties of the materials were measured and discussed. The results showed that ER properties of the fluids were improved as increase in the disperse phase concentration and as increase in the electric field strength. We also found that ER properties of the fluids depended on the densities of both polymer and disperse medium. Based on the results measured from two disperse mediums, the disperse medium with a closer match in density to the polymer showed better ER properties. Several key physical properties of the polymer were also measured by FTIR, thermogravimetric analysis and scanning electron microscopy.