Thermally stable intrinsically conductive

Thermally Stable Intrinsically Conductive Polymer-Carbon Black Composites as New Additives for Plastics... 

Tliis class of material comprises structures with D = 3 or 2 (thus, more thermally stable than the D = 0 structures discussed in Section 7.6.2) containing intrinsic protonic species (H, OH, H3O, or NH4), in contrast to extrinsic proton conductors (as discussed in Section 7.6.3). Therefore, their protonic conductivities are independent of the surrounding atmosphere, although their decomposition temperatures (as listed below in this section) should be increased at high partial pressures of water and/or ammonia. In addition, they do not contain basic components such as SrO or BaO that cause the instability of perovskites in CO2 and steam. 

One of the main limitations of intrinsically conductive polymers (ICP s) towards their wide application as conductive additives for thermoplastics is their poor thermal-oxidative stability at typical melt processing temperatures (i.e., above 200 °C). On the other hand, the use of high surface area carbon blacks (CB) as conductive additives is limited due to the increased melt viscosity of their blends with thermoplastics. Eeonomers are a new class of thermally stable, chemically neutral, and electrically conductive composites made via in-situ deposition of conductive polyaniline (PANI) or polypyrrole (PPY) on CB substrates. Eeonomer composites are more stable (up to 300 °C) than pure ICP s and more easily processible with thermoplastics than CB. Use of Eeonomers as conductive additives for plastics lead to compounds with improved electrical, mechanical, and processing properties. By varying Ae conductive polymer to CB ratio, it is possible to fine tune the polarity of Eeonomer composites and achieve very low percolation thresholds. This control is possible because of preferred Monomer localization at the 2D phase boundary of the immiscible polymer blends. 

Eeonomers are a new class of conductive additives for thermoplastics made via in-situ deposition of intrinsically conductive polyaniline or polypyrrole on carbon black. Eeonomers are highly thermally stable, pH neutral conductive materials that are compatible with the chemistry and melt processing conditions of acid sensitive polymers. Compounding studies with thermoplastics indicate better electrical, mechanical, and melt flow properties of Eeonomer blends as compared to blends with traditional carbon blacks. In co-continuous plastic blends it was possible to fine tune the polarity of Eeonomer by varying the conductive polymer to CB ratio. The same variation affords very low percolation thresholds due to preferred Eeonomer localization at the 2D phase boundary. 

The bridged transition metal complexes described in Sections 5 and 6 form one of the first stable systems exhibiting intrinsic electrical conductivities, without external oxidative doping, and possess a strong potential for future applications, e.g. as molecular wires in miniaturized machines. Due to their high thermal and chemical stability they are also of interest for technical applications like antistatically equipping foils and fibers [210]. Some of these complexes, e.g. PcTiO also possess excellent photoconductivities [134] and can be used in Xerox machines. 

These fluorinated PPPs led to original membranes endowed with a good thermal stability (films were stable in air up to 310 °C), interesting electrochemical properties, very low methanol crossover (its intrinsic permeability to methanol was lower than that of Nation for the same thickness), high ion exchange capacity (1.3 mequiv./g), and satisfactory conductivity (8.5 mS/cm) for a thickness of 40 pm. AU these relevant characteristics show that these membranes are potential candidates for direct methanol fuel cells [111b]. 

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