Conducting polymer composites

Conducting polymer composites have also been formed by co-electrodeposition of matrix polymer during electrochemical polymerization. Because both components of the composite are deposited simultaneously, a homogenous film is obtained. This technique has been utilized for both neutral thermoplastics such as poly(vinyl chloride) (159), as well as for a large variety of polyelectrolytes (64—68, 159—165). When the matrix polymer is a polyelectrolyte, it serves as the dopant species for the conducting polymer, so there is an intimate mixing of the polymer chains and the system can be appropriately termed a molecular composite. 

Formation Processes and Properties of Conducting Polymer Composites... 

Distribution of Filler in Conducting Polymer Composites Based on... 

Conducting polymer composite materials (CPCM) — artificial media based on polymers and conductive fillers, have been known since the early 1940s and widely used in various branches of science and technology. Their properties are described in a considerable number of monographs and articles [1-12]. However, the publications available do not clearly distinguish such materials from other composites and do not provide for specific features of their formation. 

Conducting polymer composite materials are typical disordered structures consisting of randomly (or according to a certain law) arranged particles of a conducting filler that are submerged into a polymer medium. In this case the filler particles have macro-... 

In the case of the filler localization in one of the polymer components of the mixture, an increase of the portion of the second unfilled polymer component in it entails sharp (by a factor of lO10) rise of a in the conducting polymer composite. In this case the filled phase should be continuous, i.e. its concentration should be higher than the percolation threshold. 

One more fact, important in practice, lies in that a of the compositions based on heterogeneous blends of polymers obtained by the method 3, depends considerably on mixing temperature Tm. This is bound up with a variation of the polymer viscosity with the temperature on being introduced into the polymer mixture, a filler becomes distributed mostly in the less viscous polymer and, if the viscosity of polymers is almost the same, it is distributed comparatively uniformly and a of the composition decreases. Therefore, the dependence of a of the conducting polymer composite on Tm has a minimum (by a factor of 102 to 104) in the Tm region when the viscosities of the polymer components are close. 

It is well known, that under industrial conditions a method of introducing filler into the polymer mixture is used. In this case, the filler is introduced in the form of paste containing up to 60 per cent water in order to reduce viscosity, As heating is affected by viscous friction, the temperature conditions are not stable on mixing and, therefore, conductivity of the conducting polymer composite becomes unreproducible. Up to now this factor has not been taken into consideration. 

However, the relaxation process is rather slow whereas thermoplast processing calls for almost instantaneous cooling of the melt after molding and due to this fact the chain structure is not restored. From this it follows that in molding a conducting polymer composite the cooling of the melt should have a speed comparable to the speed of restoration of the filler secondary structure, otherwise the conductivity of the polymer composite will be reduced. 

Natural graphite and synthetic graphite were used as fillers for the manufacture of conducting composite materials by the polymerization filling technique [24, 53-56], The manufacture of conducting polymer composite materials by this technique on the basis of some kinds of carbon black is also known [51, 52],... 

GuT VE, Shenfil LZ (1984) Conducting polymer composites, Moscow, Chemistry (in Russian)... 

Oxidized conducting polymers, or conducting polymer composites can be envisaged as stores of anions or cations, respectively. As stated earlier, these ions can be liberated, under a well-defined control, in a solution. This idea is being developed in order to store ions of pharma-... 

The authors thanks Dr. M. Katsitadze - for the synthesis of l,3-dimethyl-l,3-dioctyledisiloxane and 1.4-bis(dihydridcdimctylhyl)bcnzcnc, also Prof. Dr. Aneli and Dr. D. Gventsadze - for study of created electro-conducting polymer composites. 

Note 4 An intrinsically conducting polymer should be distinguished from a conducting polymer composite and from a solid polymer electrolyte. 

Note 6 Electric conductance of a nonconducting polymer can be achieved by dispersing conducting particles (e.g., metal, carbon black) in the polymer. The resulting materials are referred to as conducting polymer composites or solid polymer-electrolyte composites. 

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