ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The effects of concentration and aspect ratio of carbon fiber and temperature on volume resistivity of polychloroprene-carbon fiber composites have been studied. The critical concentration of fiber wherein a sharp transition of electrical performance occurs from insulative range to conductive range is in the range of 5 to 10 phr for fibers of higher aspect ratio (∼ 100) and in the range of 20 to 25 phr for fibers with lower aspect ratio (∼ 25). Experimental values of electrical conductivity agreed reasonably well with the calculated values from a theory based on probability of formation of conductive network. Heating and cooling curves in the variation of volume resistivity with temperature do not follow the same path and results in a “hysteresis loop,” up to carbon fiber loadings of 30 phr. Such loops disappear at 40 phr loading. The activation energy of conduction for carbon fiber-filled polychloroprene varies from 1.10 × 10-20 to 0.96 × 10-20 J. Linearity in current-voltage relation was observed at room temperature. Increasing interfiber distance at higher temperatures disrupts the linear relation. The type of carrier in carbon fiber-filled polychloroprene thermovulcanizate was found to be n-type. The carrier concentration and drift mobility determined by studying the Hall effect were found in the range of 2.5 × 1022 to 2.90 × 1025 m-3 and 1.66 × 10-4 to 14.25 × 10-4 m2 V-1 s-1, respectively.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760320611
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