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Title: Electrical and dielectric properties of foam injection-molded polypropylene/multiwalled carbon nanotube composites

A combination of high dielectric permittivity (ε′) and low dielectric loss (tan δ) is required for charge storage applications. In percolative systems such as conductive polymer composites, however, obtaining high ε′ and low tan δ is very challenging due to the sharp insulation-conduction transition near the threshold region. Due to the particular arrangement of conductive fillers induced by both foaming and injection molding processes, they may address this issue. Therefore, this work evaluates the application of foam injection molding process in fabricating polymer nanocomposites for energy storage. Polypropylene-multiwalled carbon nanotubes (PP-MWCNT) composites were prepared by melt mixing and foamed in an injection molding process. Electrical conductivity (σ), ε′ and tan δ were then characterized. Also, scanning and transmission electron microscopy (SEM and TEM) was used to investigate the carbon nanotube’s arrangement as well as cellular morphology. The results showed that foam injection-molded composites exhibited highly superior dielectric properties to those of solid counterparts. For instance, foamed samples had ε′=68.3 and tan δ =0.05 (at 1.25 vol.% MWCNT), as opposed to ε′=17.8 and tan δ=0.04 in solid samples (at 2.56 vol.% MWCNT). The results of this work reveal that high performance dielectric nanocomposites can be developed using foam injection molding technologiesmore » for charge storage applications.« less
Authors:
; ; ; ;  [1] ;  [2]
  1. Microcellular Plastics Manufacturing Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, Ontario, Canada M5S 3G8 (Canada)
  2. Leibniz-Institut für Polymerforschung Dresden e.V. (IPF), Hohe Strasse 6, D-01069 Dresden (Germany)
Publication Date:
OSTI Identifier:
22391869
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1664; Journal Issue: 1; Conference: PPS-30: 30. International Conference of the Polymer Processing Society, Cleveland, OH (United States), 6-12 Jun 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; CARBON NANOTUBES; DIELECTRIC MATERIALS; ELECTRIC CONDUCTIVITY; FILLERS; FOAMS; MOLDING; MORPHOLOGY; NANOCOMPOSITES; PERMITTIVITY; POLYPROPYLENE; RELAXATION LOSSES; SCANNING ELECTRON MICROSCOPY; SOLIDS; TRANSMISSION ELECTRON MICROSCOPY