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Conductivity of polyolefins filled with high‐structure carbon black
Author(s) -
Yu J.,
Zhang L. Q.,
Rogunova M.,
Summers J.,
Hiltner A.,
Baer E.
Publication year - 2005
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.22238
Subject(s) - carbon black , materials science , percolation threshold , conductivity , polypropylene , percolation (cognitive psychology) , electrical resistivity and conductivity , composite material , percolation theory , dispersion (optics) , arrhenius equation , polymer chemistry , activation energy , chemistry , physics , natural rubber , quantum mechanics , neuroscience , optics , biology
The electrical conductivities of various polyolefins filled with a high‐structure carbon black (CB) were studied. Typical percolation behaviors were observed in all of the materials studied. At a critical CB content, which defined the percolation threshold, CB formed conductivity pathways, and resistivity fell sharply from a value characteristic of an insulator into the range of 10–100 Ω cm. The dependence of the percolation threshold on the matrix viscosity was understood in terms of competing effects on CB dispersion during blending and CB flocculation during compression molding. For the conditions used in this study, polypropylene with a melt flow index of about 50 was optimum. Flocculation in the quiescent melt was studied directly by atomic force microscopy. Conductivity pathways formed over time by CB agglomeration. The temperature dependence of the percolation time was described by an Arrhenius relationship. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1799–1805, 2005