Thermally stable conducting composites based on a carbon black‐filled polyoxadiazole matrix

Abstract

New thermally stable conducting materials can be obtained by dispersing conducting carbon black into poly(4,4Ј-diphenylether-1,3,4-oxadiazole) (POD-DPE) solution in NMP. The blend preparation process resulted in quite good dispersed composite and a relatively low percolation threshold (around 5 wt % of CB). The effect of the compressive stress on the resistivity of composite has been evaluated. The resistivity decreases continuously as the applied pressure is increased. In addition to the electrical conductivity, the presence of carbon black resulted in higher thermally stable materials. The thermal stability, electrical conductivity, and pressure-sensible characteristics make this conducting material a good candidate for application in manufacture of pressure sensors for high temperature ambient. This material shows a typical semiconductor behavior, characterized by an increase of conductivity with the temperature.

Synthesis and properties of new polyimide/clay nanocomposite films

“…Outstanding thermal stability is ascribed to the oxadiazole ring being electronically equivalent to the phenylene ring structure, which is known to be highly thermally resistant. Thus, polymers containing 1,3,4oxadiazole moieties are considered as alternatives for the development of heat-and flame-resistant, semiconducting, fibre-forming and thermally stable membranes for gas separation purposes (Hsiao and Chiou 2001;Gomes and Nunes 2003;Souza et al 2004).…”

Thermally stable electromagnetic interference shielding material from polysulfone nanocomposites: Comparison on carbon nanotube and nanofiber reinforcement

“…An insulating material is converted to conductive one by the incorporation of a critical concentration of conductive additive (called percolation threshold). At this critical filler concentration, a continuous conducting path of filler particles is formed across the volume of the composite . In order to estimate the percolation threshold of MWCNTs and CNFs in PSU nanocomposites, the experimental conductivity data have been fitted to the following power law equation of percolation theory .…”

Poly(oxadiazole)s

“…Further, the composite shows a typical semiconductor behavior, characterized by an increase of conductivity with temperature. 39 The thermal and electrical properties and pressure sensitivity make this compound a good candidate for the application in manufacture of pressure sensors for high ambient temperatures.…”