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Composites of polyvinylidene fluoride (PVDF) and short carbon fibers (SCFs) with different aspect ratios of the SCFs were prepared by the solution casting technique. The electrical percolation thresholds of the composites are highly influenced by the SCF aspect ratio calculated using both the Sigmoidal Boltzmann model and classical percolation theory. It was observed that the percolation threshold of PVDF/SCF composites decreases with an increase in the aspect ratio of the SCFs in the PVDF matrix. Different theoretical models were used to check the alignment of the SCFs in the PVDF matrix. The applicability of the theoretical models was tested to predict the composition‐dependent electrical conductivity at different SCF loadings and aspect ratios and the predictions were compared with experimental results. The effect of the fiber aspect ratio on the AC electrical conductivity was also investigated. Finally, the transparency of the composites was tested with the help of UV−visible spectroscopy and exhibits an SCF loading dependence in the PVDF matrix. © 2016 Society of Chemical Industry

In this investigation, polyvinylidene fluoride (PVDF)/short carbon fiber (SCF) composites have been prepared by solution casting technique to enhance electrical and dielectric properties with very low‐electrical percolation threshold (0.5 phr SCF). The effect of SCF content on mechanical, thermal and morphological properties of the composites have also been investigated. The mechanical properties of the composites are found to reduce compared to neat PVDF due to poor polymer–filler interaction which can be concluded from FESEM micrographs showing poor bonding between PVDF and SCF. The PVDF/SCF composites exhibit either positive temperature coefficient effect of resistivity or negative temperature coefficient effect of resistivity depending on the loading of SCF in the polymer matrix. The change in conductivity during heating–cooling cycle for these composites shows electrical hysteresis along with electrical set. The melting point of the composites marginally increases with the increase in fiber loading in PVDF matrix as evidenced from DSC thermograms. X‐ray diffraction analysis reveals the crystallinity of PVDF decreases with the increase in SCF loading in matrix polymer. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39866.