EFFECT OF SELECTED PROCESSING PARAMETERS ON SOLUTION PROPERTIES AND MORPHOLOGY OF POLYANILINE AND IMPACT ON CONDUCTIVITY

Interchain H-bonding between amine and imine sites in emeraldine base (EB) results in aggregate formation. The aggregation is present in the as synthesized EB; the level of aggregation is dependent on the polym erization conditions. Reduction of EB to the leucoemeraldine form elim inates the imine sites and thus, the interchain H-bonding and the aggr egation are also eliminated. The degree of aggregation in the EB powde r determines the solubility and solution characteristics of the polyme r. Solvents such as m-cresol and additives such as LiCl which dope EB are most efficient at solvating the polymer and thus, deaggregating th e chains. Deaggregation facilitates chain expansion. The degree of agg regation and chain expansion in EB solutions significantly impact the overall properties of both the non-doped and doped polymer such as the optical absorption, conductivity and degree of crystallinity. Crystal line EB films are attained from solutions consisting of low polymer co ncentration where the polymer is well solvated and highly deaggregated . Highly crystalline nonstretched EB films are attained by the introdu ction of a plasticizer which imparts local mobility allowing the chain s to crystallize.