Conductive poly(vinylidene fluoride)/polyethylene/graphene blend‐nanocomposites: Relationship between rheology, morphology, and electrical conductivity

Abstract

Relationship between rheology, morphology, and electrical conductivity of the poly(vinylidene fluoride)/polyethylene/graphene nano-platelets ternary system (PVDF/PE/GnP) were investigated. All the blend nanocomposites were prepared via a two-step melt mixing method. GnP (0.75 and 1.5 wt %) was first compounded with PVDF and then the resulted premixtuers were melt mixed with PE to achieve the desired compositions. The corresponding reference nanocomposites and filler-less blends were also prepared. Effect of an interfacial agent (PEMA; maleic anhydride grafted polyethylene) was also studied in this work. The results of rheological analysis in conjunction with the Raman spectroscopy experiments revealed that GnP had higher affinity to PVDF than PE, which in turn led to creation of conductive networks of GnP (1.5 wt %) in PVDF matrix exhibiting the electrical conductivity of about 10 22 (S/cm). Double percolated micro-structure was predicted for the PE/PVDF 40/60 (wt/wt) blend containing low GnP content (0.9 wt %) and confirmed via direct electron microscopy and conductivity analysis. Using 5 wt % of the PEMA reduced the conductivity to 10 25 (S/cm) and further increase in PEMA content to 10 wt % led to non-conductive characteristics. The latter was attributed to the migration of GnP from the PVDF phase to PE/PEMA phase and hence disturbance of double percolated micro-structure. V C 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46333.

Study on crystalline structure of poly(vinylidene fluoride)/polyethylene/graphene blend‐nanocomposites

“…In recent decade, special attention has been paid on polymeric blend‐nanocomposites as these systems benefit the advantages of both polymer blends and polymer nanocomposites, simultaneously . Developing of the conductive polymeric systems with low conductive filler contents is one of the most important issues in polymeric blend‐nanocomposites . Using the concept of “double percolation” in conductive polymeric systems is a new strategy to effectively reduce the percolation threshold concentration of the used conductive filler .…”

“…Developing of the conductive polymeric systems with low conductive filler contents is one of the most important issues in polymeric blend‐nanocomposites . Using the concept of “double percolation” in conductive polymeric systems is a new strategy to effectively reduce the percolation threshold concentration of the used conductive filler . Double percolation is referred to a microstructure in which the filler is preferentially localized in continuous phase of an immiscible blend or at the interphase of a blend with co‐continuous morphology.…”

“…Double percolation is referred to a microstructure in which the filler is preferentially localized in continuous phase of an immiscible blend or at the interphase of a blend with co‐continuous morphology. Double percolated systems exhibit lower percolation concentration of the filler compared to single‐phase polymeric systems …”

“…In our previous work, a strategy of reducing the content of graphene nano‐platelets (GnPs) in conductive polyethylene/poly(vinylidene fluoride) PE/PVDF blends was employed. In that work the relationship between rheology, morphology and electrical conductivity of the PVDF/PE/GnP ternary systems were systematically studied.…”

“…Considering the application of each polymorphism of the PVDF, the main objectives of present work are: (a) study the effects of the GnP on crystallization behavior of PVDF/GnP nanocomposites. On the other hand, as the PE counterparts of the blend studied in our previous work and this study (PVDF/PE blend) is a semi‐crystalline polymer also, and considering the fact that localization of a nano‐filler such as GnP in each phase would affect the nucleation type and the rate of crystal growth it was decided to systematically study the crystallization behavior of the PVDF/PE blends (b) to follow the flow‐induced crystallization behavior of the blends in the presence of GnP using rheological characterizations.…”