Electroconductive polymers polyacetylene

Common conductive polymers are polyacetylene, polyphenylene, poly-(phenylene sulfide), polypyrrole, and polyvinylcarbazole (123) (see Electrically CONDUCTIVE POLYMERS). A static-dissipative polymer based on a polyether copolymer has been announced (124). In general, electroconductive polymers have proven to be expensive and difficult to process. In most cases they are blended with another polymer to improve the processibility. Conductive polymers have met with limited commercial success. 

Polyacetylene is expected to be an electroconductive polymer. Polymerization with organorhodium compounds easily affords a highly stereoselective polymer. For example, the polymerization of phenylacetylene with [(NBD)RhCl]2 in a triethylamine solvent affords a polymer having a cis-transoid structure with mol. wt. 520000 in 93% yield [124,125]. 

Polyacetylene has promise as a polymeric electroconducting material [26-31]. The simplest way to obtain this polymer is by polymerisation of acetylene, although alternative methods involving the metathesis polymerisation of cyclic polyenes are also effective. 

The size of electroconductivity compressed samples MoClj j(C3(, jHgQ j), measured at a direct current at a room temperature-( 1.3 3.3) 10 Ohm -cm is in a range of values for a trans-polyacetylene and characterizes a composite as weak dielectric or the semiconductor. The positioned size of conductivity of samples at an alternating current tr = (3.1 4.7)-10 Ohm cm can answer presence of ionic (proton) conductivity that can be connected with presence of mobile atoms of hydrogen at structure of polymer. 

Conductive polymers, such as polyacetylene, polythiophene, polypyrrole, polyisothianaphthene, polyethylene dioxythiophene, polyaniUne, and so on, have interesting properties that make them suitable for use in PEMFCs (Heeger, 2001 Shirakawa, 2001). Their electroconductivity and noncarbon functionalities allow some of them to perform effectively as alternative carbon catalysts or with carbon supports to enhance their catalytic effects. Huang et al. utilized polypyrrole as a conductive polymer support for a platinum catalyst active for the ORR (Huang et al., 2009). Their results show significant resistance to carbon corrosion and improved conductivity over traditional Pt/C catalysts. They report that the platinum on polypyrrole catalyst (Pt/Ppy) has well-dispersed platinum particles of about 3.6 nm in diameter. CV scans up to 1.8 V revealed that there was httle carbon support corrosion on the Pt/Ppy and a twofold increase in activity than Pt black at 0.9 V. 

---