Synthesis and electrorheological characteristics of polyaniline derivatives with different substituents

Various polyaniline (PANI) derivatives from different monomers such as o-methoxyaniline (MOA), o-ethoxyaniline (EOA), o-methylaniline (MA) and o-ethylaniline (EA) were chemically synthesized and then examined for their electrorheological (ER) application, by dispersing the synthesized PANI derivative particles into a non-conducting oil. Characteristics of PANI derivative particles were also studied by FT-IR, TGA and SEM analysis. Depending on the type of substituents in the polymer chain, electrical conductivity of the particles varied, possibly due to a steric hindrance of the substituent and different interchain interaction. From the steady shear ER measurement, the conductivity of particle was found to affect the ER property of the suspension.