ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
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:
Insulator-to-metal transition of polyimide films can be performed by pyrolysis at high temperature as proposed by the authors. The maximum conductivity of the polyimide pyrolyzed at 950°C for 0.5 h in a nitrogen atmosphere was measured to be 248 S/cm. The structure, electrical, and magnetic properties of the pyrolyzed polyimide depend on the pyrolytic conditions, such as pyrolytic temperature and time. The pyrolysis process consists of carbonization and graphitization processes, and a distinguishable pyrolytic temperature between them was estimated to be about 700°C. In the carbonization process, an increase in conductivity with the pyrolytic temperature may be due to the formation of localized charge carriers. In the graphitization process, on the other hand, it is suggested that the delocalization of charge carriers is responsible for the high conductivity observed from pyrolytic temperature higher than 700°C. © 1996 John Wiley & Sons, Inc.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
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