Improved solution stability and spinnability of concentrated polyaniline solutions using N,N′-dimethyl propylene urea as the spin bath solvent

It is widely known that the intrinsically conductive polymer (ICP) polyaniline is soluble in NMP solvent in its nonconducting base form. However a concentrated polyaniline/NMP solution (>5%) is unstable and rapidly forms gels at room temperatures. We have found that the gelation time and solution stability of polyaniline in DMPU is greatly increased and that this solvent may be suitable for use as a spin bath for the wet spinning of polyaniline fibers in the base form. We report in this paper some initial rheology data on solutions of PANI using NMP, NMP/LiCl, and DMPU as the solvent. All examined PANI solutions showed a similar rheological behavior in that the solutions became more shear dependent with increasing concentrations or increased aging time. The spinnability of PANI solutions was superior when DMPU is used as the spin bath solvent. NMP/LiCl was also examine since this solution tends to prohibit coagulation of PANI in solution.