Structure/Property Relationships for Poly(Vinylidene Fluoride)/Doped Polyaniline Blends

Abstract

Poly(vinylidene fluoride) (PVDF) and its blends with polyaniline (PANI) doped with dodecylbenzene sulfonic acid (DBSA) were characterized by electrical conductivity, differential scanning calorimetry (DSC) and X‐ray scattering techniques.

The onset of an infinite cluster (InC) of conducting, highly anisometric PANI/DBSA particles in PVDF/(PANI/DBSA) blends was observed at the percolation threshold as low as w*≈3.5 wt.%. The small angle X‐ray scattering (SAXS) data confirmed the expected spatial organization of PANI/DBSA needles into fractal‐like structures above w*. A slight decrease of both the DSC and the wide‐angle X‐ray scattering (WAXS) degrees of crystallinity of PVDF with the PANI/DBSA mass content w was explained by strong interactions at the PVDF/(PANI/DBSA) interface resulting in the loss of crystallizability of a fraction of sterically immobilized chains of PVDF in boundary layers around PANI/DBSA particles. The available data suggest that the conductive paths within InC of PANI/DBSA in PVDF/(PANI/DBSA) blends were formed primarily by the end‐to‐end contacts of PANI/DBSA fibrils.

Keywords:

• poly(vinylidene fluoride)
• polyaniline doped with dodecylbenzenesulfonic acid
• conductivity
• infinite cluster
• boundary layers

Acknowledgment

Thanks are due to Dr. V.I. Shtompel for help with the X‐ray measurements. Kind donation of PVDF latex (Kynar 1000) by Atofina (currently Arkema) is also gratefully acknowledged.