NEW AROMATIC BENZAZOLE POLYMERS - II - SYNTHESIS AND CONDUCTIVITY OF BENZOBISTHIAZOLE-CO-POLYMERS INCORPORATED WITH 4-N,N-DIMETHYLAMINOTRIPHENYLAMINE GROUPS

New aromatic benzobisthiazole copolymers containing 10-70 mol % of 4-N ,N-dimethylamino-triphenylamine functionality were prepared from the r espective dinitrile or dicarboxylic acid monomers, terephthalic acid, and 2,5-diamino-1,4-benzenedithiol dihydrochloride in polyphosphoric a cid. At the first approximation, the copolymers containing 10 mol % or less of the triarylamino moieties in the polymer chains still preserv e the capability to form anisotropic (nematic) solutions at 10 wt % po lymer concentration. This is an important requirement for processing t he copolymers into fibers and films with good to excellent mechanical properties. Films with good mechanical integrity were cast from the di lute methanesulfonic acid solutions of the copolymers under reduced pr essure. They showed electrical conductivity values of the order of 10( -11)-10(-10) S/cm in pristine state, with four to seven orders of magn itude increase upon exposure to mild oxidizing agents such as iodine v apor. On the contrary, the parent polymer, poly(p-phenylene benzobisth iazole) is an insulator with conductivity of less than 10(-12) S/cm, a nd its conductivity does not improve at all with exposure to iodine va por. (C) 1998 John Wiley & Sons, Inc.