Influence of manufacturing on electrical performances of graphite nanoplatelet filled polystyrene
Paper in proceedings, 2011

Manufacturing strategy is important for the appropriate incorporation of filler into a polymeric matrix, and this in particular refers to nanofilers. Direct-graphite nanoplatelets (GNP) were used as filler in polystyrene (PS). The as-received GNP material contained microscopic size agglomerates formed by nanoscopic size graphite nanoplatelets. Refining of the microagglomerates (break-up) and production of graphene layers (exfoliation) desirably needs to take place during manufacturing. Herein, several melt processing methods used to prepare GNP/PS are in focus. The manufacturing methods used include both, melt and solvent routes, and include elongational flow mixing (EFM), high shear energy micro compounding, roll-milling/calendering, and Brabender mixing chamber, as well as sonication and surfactant assisted solvent processing using N-methyl-pyrrolidone (NMP). We analyze particle break-up and exfoliation, and the effects on electrical conductivity and surface smoothness of the composite, both of importance in high-voltage applications. The composite is characterized by melt rheology, Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) with MeX surface topography software, optical microscopy with image analysis, X-ray Diffraction (XRD), and electrical resistivity measurements. We find that manufacturing processes influence the materialĀ“s morphology and properties in different ways. As could be expected, sonication and surfactant assisted solvent processing yielded both good deagglomeration and production of thin graphene stacks/layers. Elongational flow dispersive mixing, studied here using a recently developed mixer (RMX, Scamex, France), efficiently refines the GNP microagglomerates, and the particle break-up is closely comparable to that in solvent processing. Both the processes yield composites having smoother surfaces compared to the ones from other processing methods. Solvent processing and micro-compounding are more efficient than the other processes in the production of exfoliated thin graphene stacks/ layers. Thin graphene stacks/layers, particularly, provide electrical conductivity, at lower amount of filler content. Acknowledgments: The Swedish Foundation for Strategic Research (SSF) financial support is acknowledged (HP, MR, RWR).

Author

Henrik Persson

Chalmers, Materials and Manufacturing Technology, Polymeric Materials and Composites

J. Rondin

M. Bouquey

Reinhard Miller

Mikael Rigdahl

Chalmers, Materials and Manufacturing Technology, Polymeric Materials and Composites

Rodney Rychwalski

Chalmers, Materials and Manufacturing Technology, Polymeric Materials and Composites

NT11 International Conference on Science and Applications of Nanotubes, University of Cambridge, July 11-16, Cambridge (UK), 2011

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Materials Science

Subject Categories

Materials Engineering

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Created

10/7/2017