A new class of composite materials, reviewing and summarizing the application value and blending methods of their conductive mechanisms, and discussing the different blending and processing technologies, pointed out that the mechanical blending method is the most feasible for large-scale production. The means), male, and Ph.D., the research direction is for conductive composite communication contacts, conductive materials, which are converted by a chemical or electrochemical "doping" of a polymer having a conjugated c bond from an insulator to a conductor. A class of polymer materials, such as polypyrrole (PPy) polyaniline (PAni) polyacetylene (PA) and so on. The physicochemical properties of this type of material, such as room temperature conductivity, can vary within the semiconductor metal state of the insulator (10-9 to 105 s/cm). This is by far unmatched by any material, not only for electromagnetic shielding. Electrostatic molecular wires and other technologies can also be used in areas such as optoelectronic devices and light emitting diodes (LEDs); their doping and dedoping processes are completely reversible, and if combined with high room temperature conductivity, they can become secondary batteries. The ideal electrode material, so as to realize the all-plastic solid battery; In addition, the process of doping and dedoping is accompanied by the change of color, which can realize electrochromism, which has great application prospects. However, the disadvantages are also obvious. Although it has good electrical conductivity, it has many disadvantages such as difficulty in insolubilization, poor electrical conductivity, and high cost, which limits the scope of application. Therefore, it is very important to carry out in-depth research and improvement, and to explore the potential of its application. Many research groups are dedicated to this research and have obtained encouraging results. The specific conditions are summarized as follows.

1Technical means to improve the ICP processability Because intrinsically conductive polymers are not easily dissolved, seriously affecting their processability, limiting the scope of application of non-doped intrinsic conductive polymer itself is very weak conductivity, to make it show the conductor The characteristics of all chemical worlds are that the intrinsically conductive polymer must be doped, that is, the charge transfer or oxidation-reduction reaction occurs on the conjugated molecular chain, such as the conductivity of polyaniline is controlled by the degree of doping or the oxidation state. In the middle oxidation state, the conductivity of the most hydrophilic polymer also significantly affects the conductivity of the composite. The higher the degree of polymerization, the smaller the energy gap between the valence band and the conduction band, and the higher the conductivity, the higher the degree of polymerization. The compatibility of the system is detrimental to the processability because the nature of the ICP itself determines its difficult to melt properties, coupled with poor environmental stability of inorganic acid dopants, easy migration, so that the polarity of the ICP chain, the role of strong intermolecular chain, The decrease of the solubility will cause great obstacles to processing. Therefore, Cao Yu proposed to use organic sulfonic acid instead of inorganic acid for doping in the doping process to improve its processability. For the theory of "counter ion induction", polyaniline mainly has two conformations, such as (1) reduced state "brown emeraldine", which is almost non-conductive; (2) semi-oxidized green protonated "emeraldine", which Is the most important conductive form of polyaniline, at this time the highest conductivity after doping, (3) blue protonated "aniline black" is a fully oxidized state, the conductivity is rather low, (4)-( 5) For the doping process, A- is a counterion for protonic acid. In the last decade, based on this idea, many new dopings have been adopted, such as the use of dodecylbenzenesulfonic acid (DBSA) camphorsulfonic acid ( CSA), p-toluenesulfonic acid and other functionalized sulfonic acids, used to dope polyaniline, soluble in organic solvents and because the chain ends of the counter ions are generally hydrophobic, and the role of plasticizer, improved The compatibility of the resin is generally related to the matrix resin. The blending process includes some special processing methods and modification methods, such as the use of a polymer emulsion to modify the electrochemical film-forming adsorption polymerization, and the access to sulfonic acid groups. Modified methods, the most commonly used can be divided into the following two types of tools 1 .1 Mechanical blending To achieve large-scale industrial production, blend it with general-purpose resin with good mechanical properties and processability, and melt blending is the most feasible processing method. Not only has a good permanent antistatic ability, stability greatly improved, but also to maintain the mechanical properties of the parent polymer, but ICP itself is easy to decompose and can not be melted, so we must first improve its stability and increase its processing temperature. The reported processing temperature of ICP composites generally cannot exceed 240C, and the base resin of choice must be able to process below this temperature. The key to the blending of intrinsically conductive polymer and general resin is to form the conductive channel of the conductive polymer itself. According to the percolation theory proposed by Wessling, the abrupt change in conductivity, that is, the formation of the conductive percolation network can be considered as a phase. The transition, that is, the sudden dispersion of conductive particles from a fully dispersed state to a flocculation (flocculation), in fact, influences the percolation concentration and the interface state between the ICP particles and the matrix resin, rather than simply seeking for conductive polymers and matrix polymers. The complete compatibility is the use of appropriate compatibility of conductive polymers with the parent polymer to form a continuous distribution of the conductive polymer phase, resulting in the so-called secondary percolation network structure, which may make "percolation value" possible.

Keeping in the range of ~2%, greatly reducing the amount of addition, reducing the cost, and improving the mechanical properties, it is possible to obtain composite polymer materials with multi-phase structural characteristics. 1.2 Solution mixing method The solution method is suitable for laboratory research, but First, the substrate and the conductive component are required to be dissolved together, and the application range is limited. ICPs doped with organic functional protic acids can be dissolved in organic solvents such as tetrahydrofuran (THF) N-methylpyrrolidone (NMP) dimethyl sulfoxide (DMSO), and many polymers such as polyvinyl alcohol (PVA) ethylene acetic acid. After the ethylene copolymer (EVA) nylon 6 (PA6) can be co-dissolved with the solvent and cast into a solvent, the volatile solvent forms a composite film that generally has a certain degree of transparency and good conductivity. If the solution is treated with ultrasonic waves, Get a very low permeability (m4) material.

1.3 In-situ compounding method is applicable to conductive coatings. Based on the principle of intrinsic conductive polymer monomer can be oxidative polycondensation under the action of oxidants (such as FeCl3). The monomer is pre-impregnated onto the matrix polymer and then in the gas phase or liquid phase polymerization. The law is deleting/crosslinking rubber bases. Synthetic poly. Anilinoline 8 polyelectrolytes with a high relative molecular mass on the bookmark6, and then polymerized under a monomer atmosphere. The composite material thus obtained can ensure that the surface has a good electrical conductivity, and the applicable matrix material can control the proper process conditions widely. The intrinsic type conductive polymer and the matrix resin can achieve the blending within the microscopic scale and can obtain the interpenetration. Or a part of the interpenetrating network structure composite conductive polymer, using this method has been obtained PAni / POM, PPY / PI, polythiophene / PS, PAni / T cyanide, PPY / PS composites and carbon black, etc. Compared with conductive particles, the percolation curve of ICP decreased more slowly. See, control studies favoring resistivity showed that the use of organic protonic acid doped ICP has higher conductivity than inorganic acid doping, which can reach 0. 92s/cm, Solvent method is more conductive than the fusion method, and the percolation value is lower. The thermal stability of the matrix polymer also affects the conductive properties of the composite. Once the matrix polymer chain relaxes, it will destroy the interior of the composite. Conductive pathways significantly reduce the conductivity.

2 Important Intrinsically Conductive Composites 2.1 Polyaniline Composites Polyaniline is easy to synthesize, has good stability to oxygen and water, is easy to obtain raw materials, is simple in synthesis, and has good anti-fouling and anti-corrosion properties. It is currently the most promising application. Intrinsically conductive polymer. For example, DBSA-doped polyaniline and SBS composites can be processed by both thermoplastic and solution, and the electrical conductivity is still in the same order of magnitude as that of pure polyaniline. Rosena uses DBSA-doped polyaniline and EPDM machinery. The elastomers with excellent mechanical and electrical properties were blended. Gu Qingchao et al. used aniline for chemical oxygenation polymerization in acidic aqueous solution to synthesize polyaniline with high molecular weight that can be dissolved in N-methylpyrrolidone. The polyaniline is compounded with a macromolecular solid-state ionic conductor-polyethylene glycol polyether urethane (PEUU-LiCl4) solution, has good compatibility, and has good comprehensive performance. After forming a direct film, a single-surface conductive composite film is formed, and the conductivity is 08s/mYang through the extrusion process, and the phosphodiester as a PAni/LDPE compound is only added when the amount is only 3% by weight. Volumetric conductivity of up to 10"4s/mTaipalus reported the preparation of PP/PAni/GF, resulting in a composite material with good conductivity and strength. Guilherme melted DBSA-doped PnAni (3:1 mass ratio) with EVA Blend, get The composite material presented has double percolation curve characteristics, which is related to the plasticization of DBSA. Some of these varieties have already entered the stage of industrialization. For example, PAni/PVC conductive composite material developed by Americhem of the United States has a PAni content of 30%. Volume resistivity of up to ten tensile strength 4.2MPa, elongation greater than 250%, can be used as a shielding material. Finnish PAnpol company doped PAni mechanically blended with PPPE ps resin to obtain a surface resistivity of 12.2 in the polypyrrole composite material Polypyrrole (PPy) is one of the conductive polymers discovered earlier and has been systematically studied. It has good thermal chemical oxidation and light stability. After doping, its conductivity is as high as 102s/m, and it is easily electrochemically formed. The dense film can be prepared by mechanical blending solution blending method, for example, Yin Wusheng reported the PMMA/PPy compound based on acrylates, tensile and machinability Excellent Jiang Jianming Ouyang uses in-situ polymerization method to adsorb PPy on the surface of PVC particles. When PPy content is used in addition to the above method to improve the ICP processability, the use of oligomers (ie, single The study of oligomers to improve the molding processability has not been carried out. The reason is that the conductivity of the oligomers is significantly lower than that of the polymers with high molecular weight. However, a large amount of experimental facts prove that when the oligomerization of 10 The room temperature conductivity of Oligomer is comparable to that of a polymer. It has been reported that this provides an experimental basis for the study of conducting oligomers due to the structural diversification of polymers and the condensed state structure of conductive polymers. The complexity brings about the uncertainty of the structural performance relationship, which hinders the in-depth study of the structural properties of conducting polymers. The oligomers have the characteristics of definite molecular structure, no organic solvent-soluble molecules, and easy crystallization. In addition, its microscopic structure is convenient for characterization, which provides more convincing evidence for the determination of the microstructure of polymer molecules, and it is possible to obtain some rules that gradually change the long conductive properties with the length of the The relationship between the molecular structure of the polymer and the generation, transport, and recombination of carriers, in order to further improve the existing soliton conduction theory and The new type of conductive mechanism lays the foundation. From the application point of view, it itself can be regarded as a new material with great application prospect. At present, in the field of permanent antistatic materials, ICP composite materials have received more and more attention, and the traditional Compared with the carbon black filler material, its color has a certain degree of adjustability, the film is semi-transparent, and its cost is low, which is a very economical and promising technology means to realize the composite and multi-functionalization of the conductive polymer. The key to the application of this technology is that from the early 1990s onwards, conductive polymers and composites with high transparency and high temperature resistance, which are mechanical properties, have been prepared, taking into consideration the electrical and optical properties as well as thermal stability of new composite materials. The research has made great progress and it is believed that these studies will lay a solid foundation for the practice of conductive polymers in existing materials, devices and theoretical work, and lay a solid foundation for applications in high-tech fields such as optoelectronic devices and aerospace. Foundation.