Physical Techniques For The Study Of Sorption Diffusion Electrical Properties And Interfacial Effects In Ordered Polymers

Physical techniques for the study of sorption, diffusion, electrical properties, and interfacial effects in ordered polymers

Scientific and Technical Aerospace Reports

Physical Techniques for the Study of Sorption, Diffusion, Electrical Properties, and Interfacial Effects in Ordered Polymers: Charge Transport and Conduction Mechanisms in Polymer Fibers

Electrical conduction in several types of polymer fibers has been investigated under a variety of environmental conditions. The configuration and circumstances of these experiments are quite different from the ordinary types of measurements reported in the literature dealing with the conductivity of thin films. Methods for separating the surface component of the total conductivity from the volume component are developed and experiments are performed on both doped and undoped samples. Experimental results indicate that the surface is the major region of current flow for some fibers. In this work, special techniques and instrumentation previously utilized by Chen and Barker have been further developed to measure electrical conductivities of small diameter polymer fibers (as small as 10 micrometers). The fibers studied included the Air Force ordered polymers PPBT (polyparaphenylene benzobisthiazole) and BBL (benzimidazo-benzophenanthroli. For comparison nylon6, nylon6, 6, polypropylene, and polyethylene also were included in the study. Several types of dopants were used in this research; these included metal-salts solutions (e.g., LiCl, NaCl, etc.), organic liquids (e.g., n-pentane, phenol, etc.) and charge transfer complex forming dopants(e.g., I2). The effect on fibers of this doping produced variations in the electrical conductivity which sometimes were surprising.