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Polymer‐based nanocomposites with good dielectric behavior have engrossed research devotion because of their distinctive benefits in electronic applications. An in situ synthetic process for the polybenzimidazole functionalized graphene oxide (GBI) and its nanocomposite with poly(vinylidene fluoride) (PVDF) is described. GBI shows good dispersion in the bulk PVDF matrix implying a strong interaction of polybenzimidazole with PVDF as evident from morphological and FTIR studies. A gradual increment of GBI in PVDF increases its piezoelectric β‐polymorph formation with a maximum of 73% for 10 wt % GBI in PVDF (GBF10) which also exhibits highest thermal stability. An exhaustive study of frequency dependent electrical properties of GBF10 indicates significantly higher dielectric constant (61), low dielectric loss (0.42), and low AC conductivity value of 1.17 × 10−10 S/cm at 100 Hz which are the key properties of a suitable capacitor. GBF10 also shows hydrophobic behavior (water uptake 2.89%) and low swelling ratio (1.143), providing an opportunity to use the composite film in fuel cell application. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 189–201 Covalently functionalized graphene oxide with polybenzimidazole (GBI) shows homogenous dispersion in poly(vinylidene fluoride)(PVDF), and the composite exhibits 73% piezoelectric β‐polymorph formation for 10 wt % GBI in PVDF (GBF10). It shows significantly higher dielectric constant (61), low dielectric loss (0.42), and a low AC conductivity of 1.17 × 10−10 S/cm at 100 Hz appropriate for a capacitor. It also shows hydrophobic behavior (water uptake 2.89%) and low swelling ratio (1.143), providing an opportunity to use the composite film in fuel cell applications. [ABSTRACT FROM AUTHOR]

A new route for the synthesis of low cost, flexible, high dielectric constant functional polymer nanocomposite is successfully fabricated by introducing molybdenum disulfide (MoS2) into poly(vinylidene fluoride) (PVDF) using polyaniline (PANI) as an interlinker. The strategy adopted is to exfoliate MoS2 (E-MoS2) by simple sonication of bulk MoS2 in N,N′-dimethyl formamide (DMF) and in situ polymerization of aniline with E-MoS2 in water to produce MoS2–PANI showing novel raspberry type morphology. MoS2–PANI shows good dispersion in PVDF matrix implying strong interaction onto the PVDF interface, and it acts as a nucleating agent for PVDF crystallization. Synergistic nucleating effect of MoS2–PANI onto PVDF led to the formation of dominant polar β-phases in the MoS2–PANI/PVDF (MPF) composite films. With 10% filler content, the MPF material shows 86% polar β-phase PVDF due to its good interaction and dispersion of MoS2–PANI. The maximum increment of dielectric constant (ε′) of that sample is 586 at 102 Hz, which is 42 times higher than that of neat PVDF and it can be well explained by interfacial polarization along with the formation of nanocapacitor network in PVDF matrix. This intriguing synthesis method of MoS2–PANI/PVDF nanocomposite will open up new opportunities for fabricating nanostructured polymer composites to produce high dielectric materials. [ABSTRACT FROM AUTHOR]