The Polyanilines: A Novel Class of Conducting Polymers.

The conductivity doped form, degree of crystallinity, tensile strength and solubility of polyaniline emeraldine oxidation state is found to be greatly dependent on the past chemical andor mechanical history of the polymer which significantly affects the ultra-structure of the material. The conductivity of the polymer increases monotonically with increase in molecular weight up to a value of 160,000 G.P.C.Mp after which it is essentially constant. A new form of polyaniline polyaniline gel which shows an anisotropic shape-memory effect under certain conditions when swelled in solvents in which it is insoluble, has been synthesized. Pernigraniline, the most highly oxidized form of polyaniline has been n-poled to give a material of conductivity 0.5 Scm. Doping and undoping occurs without degradation of the polymer backbone. A study of Donnan equilibrium effects on the protonic acid doping of polyaniline emeraldine base shows that the doping level depends noy only on the pH of the aqueous dopant medium but also on the presence of dissolved neutral salts.