Intrinsically conducting polymers ICPs processability

Blends of intrinsically conductive polymers (ICP s) with conventional thermoplastics offered a practical means of processing ICP s without sacrificing conductivity [KuUcarni, et al., 1991]. One of the major use for these blends was electromagnetic interference shielding. 

When the first intrinsically conductive polymer (ICP) was discovered by Hideki Shirakawa, Alan G. Mac-Diarmid and Alan J. Heeger at the University of Pennsylvania in Philadelphia in the late seventies, it was thought in the initial euphoria that it would not be long before such materials could be put to practical use. The idea was that it ought to be possible to process them more easily and in larger quantities than classical metallic conductors and compared with carbon-blackfilled plastics they were expected to possess better and more uniform conductivity and better mechanical properties. 

An organic polymer that possesses the electrical and optical properties of a metal while retaining its mechanical properties and processability, is termed an intrinsically conducting polymer (ICP). These properties... 

Intrinsically conducting polymers (ICPs) are electroactive long-range conjugated polymers. They generally possess reversible redox performance, while metal corrosion is also a redox process therefore, it is possible that ICPs may find application for metal anticorrosion. It is true since the early report for corrosion inhibition performance of ICPs such as polyaniline (PANI) by DeBerry [5]. After more than 20 years of development, now ICPs have received much attention, since th may be a kind of alternative anticorrosion agents instead of the toxic heavy metal in anticorrosion coating, no matter they are used alone or as composite with substrate resin. 

Another approach to EMI screening involves the use of intrinsically conducting polymers (ICP), notably polyaniline and polypyrrole which can form the basis of composite materials whose composition may be tailored to the requirements of the application. Other conducting polymers include polyacetylene, polythiophene and poly-p-phenylene. Advantages of ICP include corrosion resistance, relatively low weight, processability and tunable conductivity. 

Furthermore, intrinsically conducting polymers (ICPs) such as polyanilines (PANI), polypyrroles, and polyphenylenes have been used as part of conductive composites on account of their much higher conductivity than other polymers. They are often mixed with other polymers as investigated by Taipalus (2001) and Totsra and Friedrich (2004). On the other hand Dweiri (2007) have found the addition of PANI to a composite of PP/carbon black/graphite for bipolar plates to be unsuitable for processing due to the poor thermal stability of PANI. The company Bac2 is currently the only manufacturer to use a patented electrically conductive polymer called ElectroPhen in their composite bipolar plates. 

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. 

Figure 2.10 Process of coating intrinsically conductive polymers (ICPs) on textile yams using...

This section explains a number of terms and phenomena necessary for an understanding of intrinsically conductive polymers (ICPs) and their processing. 

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