Effect of the structure of electrically conducting polymer compositions on their properties. Review

Gul, V.Ye.

doi:10.1016/0032-3950(78)90175-2

Cited by 13 publications

(19 citation statements)

References 10 publications

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“…[5][6][7][8][9][10] It is known that in general, percolation theory is used to describe the electrical conductivity of extrinsic conductive polymer composites. Hence, the electrical conductivity for polymer composites does not increase continuously with increasing electroconductive filler content, but there is a critical composition (percolation threshold) at which the conductivity increases some orders of magnitude from the insulating range to values in the semiconductive or metallic range.…”

Section: Introductionmentioning

confidence: 99%

Conducting polymer composites of zinc‐filled urea–formaldehyde

Pinto

Maaroufi²

2005

J of Applied Polymer Sci

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This article is concerned with the preparation and characterization of composite materials prepared by the compression molding of mixtures of zinc powder and urea-formaldehyde embedded in cellulose powder. The morphologies of the constituent, filler, and matrix were investigated by optical microscopy. The elaborated composites were characterized by density, which was compared with calculated values, and the porosity rate was deduced. Further, the hardness of samples remained almost constant with increasing metal concentration. The electrical conductivity of the composites was less than 10 Ϫ11 S/cm unless the metal content reached the percolation threshold at a volume fraction of 18.9%, beyond which the conductivity increased markedly, by as much as eight orders of magnitude. The obtained results interpreted well with the statistical percolation theory. The deduced critical parameters, such as the threshold of percolation, the critical exponent t, and the packing density coefficient were in good accord with earlier studies.

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Section: Introductionmentioning

confidence: 99%

Conducting polymer composites of zinc‐filled urea–formaldehyde

Pinto

Maaroufi²

2005

J of Applied Polymer Sci

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“…[12][13][14][15][16][17] The used fillers are metal particles, metal coated particles, or carbon particles with different sizes (10 nm to some hundreds m). On a fundamental level, these materials are random heterogeneous media.…”

Section: Introductionmentioning

confidence: 99%

Non‐linear electrical conductivity of urea‐formaldehyde‐cellulose loaded with powders of different carbon fillers

Maaroufi¹,

Pinto

Paz

2005

J of Applied Polymer Sci

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This article reports on the making and characterization of composite materials prepared by compression molding of a commercial grade thermosetting resin of urea-formaldehyde filled with ␣-cellulose in powder form mixed successively with carbon black, synthetic graphite, and activated carbon. The morphology of the constituents and the composites has been characterized by optical microscopy. The porosity effect has been discussed from density measurements. Furthermore, it has been shown that the hardness of the samples remains almost constant with the increase of filler concentration. The electrical conductivity shows clearly a non-linear behavior. The observed values are lower than 10 Ϫ11 S/cm, unless the filler content reaches the percolation threshold beyond which the conductivity increases markedly by as much as ten orders of magnitude, indicating insulator-conductor phase transition. The conduction threshold depends on the filler nature. The results have been interpreted by means of the statistical percolation theory.

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“…However, to obtain high electrical conductivity with this method, high loadings of the conductive fillers are usually required, which may result in poor mechanical properties and high cost [4][5][6][7][8]. In the literature, several processing techniques have been used to lower the percolation threshold, in which electrical conductivity of composite increases by several orders of magnitude with the formation of current conductive structures [2]. These techniques are in situ polymerization of the polymer in the presence of conductive particles [9] and selective localization of conductive filler in one of the phases or at the interface of a polymer blend composed of two polymer constituents, in which filler forms the conductive network in the dispersed phase.…”

Section: Introductionmentioning

confidence: 99%

“…Especially, conductive polymer composites have received significant attention for use in various engineering applications such as sensors, antistatic coatings, electromagnetic interference shielding, and electrolytes in the fuel cells [2,3]. They are generally a synergetic combination of conductive filler and insulating polymer matrix.…”

Section: Introductionmentioning

confidence: 99%

Effect of microfiber reinforcement on the morphology, electrical, and mechanical properties of the polyethylene/poly(ethylene terephthalate)/carbon nanotube composites

Yeşil

Köysüren

Bayram

2010

Polymer Engineering & Sci

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In situ microfiber reinforced conductive polymer composites consisting of high-density polyethylene (HDPE), poly(ethylene terephthalate) (PET), and multiwalled carbon nanotube (CNT) were prepared in a twin screw extruder followed by hot stretching of PET/CNT phase in HDPE matrix. For comparison purposes, the HDPE/PET blends and HDPE/PET/CNT composites were also produced without hot stretching. Extrusion process parameters, hot-stretching speed, and CNT amount in the composites were kept constant during the experiments. Effects of PET content and molding temperature on the morphology, electrical, and mechanical properties of the composites were investigated. Morphological observations showed that PET/CNT microfibers were successfully formed in HDPE phase. Electrical conductivities of the microfibrillar composites were in semi-conductor range at 0.5 wt% CNT content. Microfiber reinforcement improved the tensile strength of the microfibrillar HDPE/PET/CNT composites in comparison to that of HDPE/PET blends and HDPE/ PET/CNT composites prepared without hot stretching POLYM. ENG. SCI., 50:2093-2105, 2010. ª 2010 Society of Plastics Engineers INTRODUCTIONRecently, there is a great interest in industry on electrically semiconductor materials with superior mechanical properties and thermal stability [1]. Especially, conductive polymer composites have received significant attention for use in various engineering applications such as sensors, antistatic coatings, electromagnetic interference shielding, and electrolytes in the fuel cells [2,3]. They are generally a synergetic combination of conductive filler and insulating polymer matrix. They exhibit a series of unique features, such as a percolation phenomenon, sensitivity to pressure, temperature and gas, improved mechanical and thermal properties.Conductive polymer composites are usually prepared by incorporating conductive fillers into polymer matrix through melt mixing either by using an extruder or an internal mixer. However, to obtain high electrical conductivity with this method, high loadings of the conductive fillers are usually required, which may result in poor mechanical properties and high cost [4][5][6][7][8]. In the literature, several processing techniques have been used to lower the percolation threshold, in which electrical conductivity of composite increases by several orders of magnitude with the formation of current conductive structures [2]. These techniques are in situ polymerization of the polymer in the presence of conductive particles [9] and selective localization of conductive filler in one of the phases or at the interface of a polymer blend composed of two polymer constituents, in which filler forms the conductive network in the dispersed phase. This phase also constitutes continuous conductive structure in the major phase, which is called as double percolation [10][11][12]. However, in situ polymerization technique is hard to apply in the industrial scale, and in the second technique the incompatible nature of the polymer constituents of th...

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Effect of the structure of electrically conducting polymer compositions on their properties. Review

Cited by 13 publications

References 10 publications

Conducting polymer composites of zinc‐filled urea–formaldehyde

Conducting polymer composites of zinc‐filled urea–formaldehyde

Non‐linear electrical conductivity of urea‐formaldehyde‐cellulose loaded with powders of different carbon fillers

Effect of microfiber reinforcement on the morphology, electrical, and mechanical properties of the polyethylene/poly(ethylene terephthalate)/carbon nanotube composites

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