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Conductive polymer composites: Influence of extrusion conditions on positive temperature coefficient effect of poly(butylene terephthalate)/poly(olefin)–carbon black blends
Author(s) -
Feller J. F.
Publication year - 2003
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.13337
Subject(s) - materials science , carbon black , composite material , extrusion , electrical resistivity and conductivity , temperature coefficient , electrical conductor , polymer , polymer blend , ethylene , coalescence (physics) , acrylate , viscosity , polymer chemistry , copolymer , organic chemistry , chemistry , catalysis , natural rubber , physics , astrobiology , electrical engineering , engineering
Processing conditions determine both the morphology and the carbon black (CB) distribution in conductive polymer composites (CPCs). Good control of these parameters is essential to obtain reproducible electrical properties. We found that for extruded tapes of poly(butylene terephthalate) (PBT)/poly(olefin) (OLE)–CB blends, an increase of both processing temperature and screw speed leads to a significant decrease of resistivity. This shift factor, more important with PBT/poly(ethylene)–CB than with PBT/poly(ethylene‐ co ‐ethyl acrylate)–CB, is attributed to viscosity variations of all compounds. A decrease of viscosity promotes CB aggregation at the PBT/OLE interface and creates larger conductive channels by coalescence. Nevertheless, the CB concentration effect appears predominant compared to the morphology effect to explain resistivity variations. This interesting finding can be used either to improve reproducibility of electrical properties or to adjust electrical properties without changing CPC formulation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2151–2157, 2004