Molecular weight of polyaniline synthesized by oxidation of aniline with ammonium persulfate and with ferric chloride

The results of molecular weight (MW) determinations by GPC on polyaniline (PAn) (as leucoemeraldine base (LEB)) synthesized by oxidation of aniline (An) with ammonium persulfate (AP) and with ferric chloride (FC) are presented together with dynamic light scattering (DLS) and viscosity measurements. After extraction with acetonitrile (AN) and tetrahydrofuran (THF), PAn shows a unimodal MW distribution. The Mn and Mw of PAn synthesised with AP and FC are: 9,900, 50,700 and 13,500, 55,300, respectively. The intensity-weighted particle size distribution (PSDI) determined by DLS in LEB solutions is also unimodal. The mean diameter of the LEB macromolecules is 5 and 7 nm for PAn synthesised with AP and FC, respectively.