Multiple threshold percolation in polymer/filler composites

被引:39
作者
McQueen, DH [1 ]
Jäger, KM
Pelísková, M
机构
[1] Chalmers Univ Technol, Dept Mat Sci & Engn, S-41296 Gothenburg, Sweden
[2] Mkt & Dev Ctr Wire & Cable, S-44486 Stenungsund, Sweden
[3] Tomas Bata Univ, Fac Technol, Ctr Polymer, Zlin, Czech Republic
关键词
D O I
10.1088/0022-3727/37/15/018
中图分类号
O59 [应用物理学];
学科分类号
摘要
Local variations in filler particle concentration and/or shape and orientation in static filler/polymer composites are modelled as distributions of percolation thresholds. The concentration variations can be due to insufficient mixing, formation of semicrystalline voids during cooling from the melt, shrinkage during polymer curing, flow during physical compression or the like. Irregular filler shapes, especially elongated shapes, reduce the percolation threshold; thus, natural variations in the shapes and orientations of filler particle aggregates lead to locally varying percolation thresholds. A distribution of percolation thresholds leads to an apparent average percolation threshold based on the conductivity below the mean percolation threshold. For filler concentrations above the apparent percolation threshold, the dielectric constant continues to increase before reaching a lowered peak value at the mean percolation threshold and then decreasing. This can explain some 'anomalous' published experimental results concerning the dielectric constant just above the percolation threshold. In the frequency plane, the percolation threshold distribution can lead to a slight reduction of the apparent critical exponents x and y of the frequency dependencies of the conductivity and relative dielectric constant, respectively. Our experimental results on ethylene butylacrylate copolymer/carbon black composites support the theory.
引用
收藏
页码:2160 / 2169
页数:10
相关论文
共 29 条
[1]   TUNNELING AND NONUNIVERSAL CONDUCTIVITY IN COMPOSITE-MATERIALS [J].
BALBERG, I .
PHYSICAL REVIEW LETTERS, 1987, 59 (12) :1305-1308
[2]   Limits on the continuum-percolation transport exponents [J].
Balberg, I .
PHYSICAL REVIEW B, 1998, 57 (21) :13351-13354
[3]   A comprehensive picture of the electrical phenomena in carbon black-polymer composites [J].
Balberg, I .
CARBON, 2002, 40 (02) :139-143
[4]   CRITICAL BEHAVIOR OF COMPLEX DIELECTRIC-CONSTANT NEAR PERCOLATION THRESHOLD OF A HETEROGENEOUS MATERIAL [J].
BERGMAN, DJ ;
IMRY, Y .
PHYSICAL REVIEW LETTERS, 1977, 39 (19) :1222-1225
[5]   PERCOLATION IN AN OIL-CONTINUOUS MICROEMULSION [J].
BHATTACHARYA, S ;
STOKES, JP ;
KIM, MW ;
HUANG, JS .
PHYSICAL REVIEW LETTERS, 1985, 55 (18) :1884-1887
[6]   ELECTRICAL-CONDUCTIVITY AND PERMITTIVITY MEASUREMENTS NEAR THE PERCOLATION TRANSITION IN A MICROEMULSION .2. INTERPRETATION [J].
CLARKSON, MT .
PHYSICAL REVIEW A, 1988, 37 (06) :2079-2090
[7]   ELECTRICAL-CONDUCTIVITY AND PERMITTIVITY MEASUREMENTS NEAR THE PERCOLATION TRANSITION IN A MICROEMULSION .1. EXPERIMENT [J].
CLARKSON, MT ;
SMEDLEY, SI .
PHYSICAL REVIEW A, 1988, 37 (06) :2070-2078
[8]   THE AC ELECTRICAL-CONDUCTIVITY OF BINARY DISORDERED-SYSTEMS, PERCOLATION CLUSTERS, FRACTALS AND RELATED MODELS [J].
CLERC, JP ;
GIRAUD, G ;
LAUGIER, JM ;
LUCK, JM .
ADVANCES IN PHYSICS, 1990, 39 (03) :191-308
[9]   ELECTRICAL-CONDUCTIVITY OF COMPOSITES - A PERCOLATION APPROACH [J].
DEBONDT, S ;
FROYEN, L ;
DERUYTTERE, A .
JOURNAL OF MATERIALS SCIENCE, 1992, 27 (07) :1983-1988
[10]  
DUBNIKOVA IL, 1999, POLYM SCI SER A, V41, P218