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Isotactic polypropylene–vapor grown carbon nanofibers composites: Electrical properties
Author(s) -
Aldica Gheorghe Virgil,
Ciurea Magdalena Lidia,
Chipara Dorina Magdalena,
Lepadatu Ana Maria,
Lozano Karen,
Stavarache Ionel,
Popa Stelian,
Chipara Mircea
Publication year - 2017
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.45297
Subject(s) - materials science , carbon nanofiber , nanocomposite , composite material , differential scanning calorimetry , tacticity , percolation threshold , polypropylene , nanofiber , glass transition , percolation (cognitive psychology) , electrical resistivity and conductivity , carbon fibers , crystallization , carbon nanotube , polymer , chemical engineering , composite number , polymerization , physics , engineering , neuroscience , biology , electrical engineering , thermodynamics
Nanocomposites have been obtained by dispersing various amounts of vapor grown carbon nanofibers within isotactic polypropylene. Thermal investigations done by differential scanning calorimetry and dynamic mechanical analysis revealed the effect of the vapor grown carbon nanofibers on the melting, crystallization, α, and β relaxations. Direct current electrical features of these nanocomposites have been investigated and related to the thermal features of these nanocomposites. The effect of the loading with carbon nanofibers on the electrical properties of these nanocomposites is discussed within the percolation theory. The percolation threshold was estimated at about 5.5% wt carbon nanofibers. The temperature dependence of the direct current conductivity is analyzed in detail and it is concluded that the electronic hopping is the dominant transport mechanism. A transition from one‐dimensional hopping towards a three‐dimensional hopping was noticed as the concentration of carbon nanofibers was increased from 10% wt to 20% wt carbon nanofiber. The possibility of a differential negative resistivity is suggested. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45297.