THE MOLECULAR-WEIGHT OF SULFONIC-ACID RING-SUBSTITUTED POLYANILINE BYLASER-LIGHT SCATTERING

The weight average molecular weight (M(w))BAR of the sodium salt of as -synthesized sulfonic acid ring-substituted polyaniline (SPAN) was det ermined by light scattering measurements. The water solution of SPAN w as first reduced with hydrazine to render the solution almost colorles s. The M(w)BAR of the reduced SPAN sodium salt was found to be 11 000. It is concluded that the lower limit of the number of ring-nitrogen u nits per polymer chain is 39 in the as-synthesized SPAN.