Study On The Synthesis And Electrorheolgical Properties Of Polyaniline Derivatives

Electrorheological fluid (ER fluid) whose rheological properties were controlled by the application of electric field, is a kind of intelligent materials, and has showed remarkable academic interest and extensive potential engineering application. In this paper, the nature of the electrorheological fluid, its development, its composition and the influence elements on ER effect have been reviewed. Polymers of o-toluidine and neutral red were synthesized; the electrorheological properties of the synthesized polymer-based electrorheological fluids were studied. The main contents are as follows:Six polyaniline(PANI) derivatives, including poly(o-toluidine) (POT), poly(neutral red) (PNR), poly(o-toluidine-co-neutral red) (POT/NR), p-toluene-sulfonic acid doping poly(o-toluidine) (TSA/POT),p-toluenesulfonic acid doping poly(neutral red) (TSA-POT/NR) and p-toluenesulfonic acid doping poly (o-toluidine-co-neutral red) (TSA-POT/NR) were synthesized by oxidative polymerization and emulsion polymerization; The molecular structure, morphology, thermal properties, dielectric properties and density of these polymers were investigated, and the ER effect based on the particles of anti-doping of the resulting polymers were investigated. The results show that all the polymer-based suspensions of silicone oil exhibited positive ER effect, the suspensions showed yield stress and the increasing viscosity with shear rate under external electric field. The anti-doping condition made great differences on the ER effect of the particle-based suspensions. The yield stress of TSA/POT and TSA-POT/NR suspensions were proportion to the square of electric field strength. Among all the polymer-based suspensions, TSA-POT/NR and TSA/POT suspensions showed best ER effect, which were ascribed to the big dielectric constant of the particles. The p-πconjugated system combined with the highly polarity of sulfonic acid group suspended on the polymer main chain made the two polymers novel capacity of bearing and transferring charges, which in turn to the big dielectric constant. It is the dielectric constant but not the conductivity of the particles that cause the different ER effect for our studied PANI-based suspensions.