Structure formation in polyaniline-based polymer blends

This paper provides evidences on the feasibility of using an in-situ deformation process to produce elongated structures of a polyaniline complex (PANI CX), embedded in the bulk of filament-like polymer composites, and longitudinally oriented along the composites' main axial direction. The polyaniline complex was thermally blended with polystyrene- polybutadiene-polystyrene (SBS) at different weight compositions, and the resultant blends were capillary extruded into filaments. The extrudates' microstructure was analysed by scanning electron microscopy (SEM). The results of the analysis revealed a phase- separated morphology in the extrudates, which consisted of elongated domains of PANI CX embedded in the bulk of the SBS. The elongated structures displayed a considerable degree of uniformity and continuity, and were preferentially oriented in the extrusion direction. The formation of these structures was ascribed to a combination of factors, the main ones including elongational and shearing flows occurring in the molten/softened blends during the processing, and the stresses transferred from the highly viscous matrix to the particles of the PANI complex filler.