Electrically active polymers electrical properties/conductivities

Multiple Heck reactions have also been applied in a number of ways to prepare polymers (Scheme 40). One-dimensionally 7r-conjugated polymers are attractive materials because of their optical and electrical properties resulting from 7r-electron delocalization along their main chains. Among these, poly(p-phenylenevinylene) (PPV) shows high electrical conductivity, large non-linear optical responses, and electroluminescent activity. One approach... 

The electrical properties of the pyrolyzed polymer differ in a number of ways from those of polyacrylonitrile. The overall conductivity increases, while the activation energy of conductivity decreases. A rough correlation is found between a0 and E of equation 15 in that a high a0 was associated with a low E (57). Increasing the degree of orientation causes an increase in conductivity but the activation energy remains unaffected. This is typical of electronic conductivity. 

T/6-Arene ruthenium and osmium offer specific properties for the reactivity of arene ligand. The activation toward nucleophiles or electrophiles is controlled mainly by the oxidation state of the metal (II or 0). Recently, from classic organometallic arene ruthenium and osmium chemistry has grown an area making significant contributions to the chemistry of cyclo-phanes. These compounds are potential precursors of organometallic polymers which show interesting electrical properties and conductivity. 

Solid polymer electrolytes (SPE) represent the newest and one of the most important (i.e. as far as potential applications are concerned) class of FIC solids. The area of polymer/salt complexes became extremely active following the work of Wright, who first reported that PEO is an excellent polymer host for a number of salts and that the resnlting polymer/salt complexes have significant electrical conductivities near room temperature. Armand extended the investigation of the electrical properties of the polymer/salt electrolytes and... 

The electrical properties of macromolecular semiconductors are generally characterized by the conductivity, the activation energy of the conductivity, the free radical concentration, and the thermal electromotive force (thermal emf). Since the polymers are usually in the form of amorphous powders, they are compressed into tablets. The contacts are either metal electrodes pressed into the surface or conductive pastes. The samples may not have any ionic conductivity (due to impurities) or surface conductivity and must be free of moisture, otherwise the conductivities will be too high. 

Electrical insulation n. Material with very low conductivity, which surrounds active electrical devices. Common electrical insulation chemicals are fluorine-containing polymers. Dissado LA, FothergUl CJ (eds) (1992) Electrical degradation and breakdown of polymers. Institution of Electrical Engineering (lEE), London. Ku CC, Liepins R (1987) Electrical properties of polymers. Hanser Publishers, New York. 

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