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Nonlinear surface electrical resistivity of graphite–polyurethane composite films
Author(s) -
Kannarpady Ganesh K.,
Mohan Bharath,
Bhattacharyya Abhijit
Publication year - 2007
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.24514
Subject(s) - graphite , electrical resistivity and conductivity , materials science , polyurethane , composite material , composite number , percolation (cognitive psychology) , percolation threshold , graphene , carbon nanotube , nanotechnology , electrical engineering , neuroscience , biology , engineering
In this article, we study the surface resistivity of graphite–polyurethane composites using voltage–current characteristics. The evolution of the percolation network of graphite in polyurethane is qualitatively studied using optical micrographs. As expected, the surface resistivity decreases as a function of graphite concentration. In particular, the surface resistivity of the 69% graphite–polyurethane composite is about four orders of magnitude lower than the surface resistivity of the 27% graphite–polyurethane composite. The electrical resistivity of the composite is found to be highly nonlinear with respect to an increasing voltage at a low graphite weight fraction. On the other hand, the nonlinearity is significantly milder at higher weight fractions. The reasons behind the nonlinearity are discussed. Very preliminary studies indicate that very low weight fractions of single wall carbon nanotubes (e.g. 2.5%) are sufficient to generate electrical conductivities comparable to much higher loading fractions (∼ 60% and higher) of the heavier graphite particles. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007