EFFECT OF DOPANT COUNTER-ANION ON TRIBOLOGICAL PROPERTIES OF POLYPYRROLE

It is known that, with careful control of conditions, polypyrrole film s with counter-ions of toluene sulphonic acid sodium salt and methane phosphonic acid sodium salt can be produced with friction coefficients comparable with or even better than PTFE, Here we now report a system atic study of polypyrrole with various planar anions for tribological bearing applications. Thus naphthalene disulphonate-doped polypyrrole has a kind of laminar structure with very good adhesion to the surface , Polymer films were electrodeposited on glass lenses and tested in a friction apparatus for friction and wear measurements. The film orient ation was measured by low-angle X-ray diffraction and the surface stru cture was evaluated by both AFM and SEM for different film thicknesses , The friction coefficient and wear rate of such bearings were measure d under loads up to 5 N and at speeds up to 30 mm s(-1) and were found to be 0.06 and 0.04 nm mm(-1) respectively. (C) 1998 John Wiley & Son s, Ltd.