Authors Alig, I. ; Hilarius, K. ; Lellinger, D. ; Pötschke, P.
Title Filler networks of carbon allotropes of different shape and dimensions in a polymer matrix
Dynamics of Composite Materials, Schönhals, A.; Szymoniak, P., ed.
Date 15.03.2022
Number 59395
Abstract Dielectric permittivity and electrical conductivity of percolating filler networks of different carbon allotropes such as carbon black (CB), multi-walled carbon nanotubes (MWCNT) , and graphite nanoplates (GNP) dispersed in a polycarbonate (PC) matrix were studied by broadband dielectric spectroscopy (BDS) and rheo-electrical measurements. CB, MWCNT, and GNP represent carbon allotropes of different shapes and dimensionalities, which build electrical conductive network structures within the polymer matrix. In a first part, the dielectric properties of solid samples with different CB, MWCNT and GNP contents were studied by BDS. The concentration-dependent dielectric properties are compared and discussed with regard to the particle shape. Since the structure of the filler network is extremely sensitive to deformations of the melt, the second part deals with rheo-electical measurements on composite melts. Under steady shear conditions, an interplay between build-up due to attractive interactions between the particles, and break-up of the network structures indicated by steady-state values of DC conductivity and viscosity can be observed. The increase of the DC conductivity in the quiescent melt after shear deformation is due to a recovery of the filler network. In order to study the orientation kinetics of the particles, additional rheo-electric measurements perpendicular to the shear flow and in flow direction were performed. The influence of particle shape and dimensions on the electrical, dielectric, and rheological properties are discussed in terms of agglomeration and break-up of the filler network and orientation kinetics of the particles in the polymer melt.
Publisher Springer International Publishing
Citation Springer International Publishing (2022) 291-333

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