Composite polypyrrole-textile

Forder et al. [70] have successfully prepared superparamagnetic conductive polyester textile composites (polypyrrole and magnetite on polyester textile fiber substrate) by a two-step deposition method, i.e., magnetite deposition and PPy deposition. 

Many applications of conducting textiles involve the formation of laminates or composites with various thermoset resins such as epoxy, imide, and rubber. The adhesion between the various layers of the composite is a critical factor in the utility of these structures. Only a few papers have addressed the adhesion of polypyrrole-coated fabrics with epoxy resins [44,451. The adhesion at the polypyrrole/textile interface is reasonably strong because of the intermolecular forces between the adsorbed polymer layer and the substrate. The adhesion at the polypyrrole/epoxy interface benefits from the po-... 

Conductive Coatings for Electromagnetic Shielding and Static-Dissipating Appiications. In addition to the RF electrochromics research discussed above, EAPs are also used as conductive coatings on textiles for radarabsorbing materials (RAMs) (420). Polypyrrole and PANI are both examples of EAPs used in composite formulations as RAMs (420,422). 

There are many applications where the physical properties of a textile substrate are combined with the electrical and shielding properties of polypyrrole. Thus polypyrrole-coated fabrics show excellent dissipation properties. In this way industrial uniforms where explosion-proof conditions or shielding fi om micro-waves are necessary can be fabricated, as well as the use of polypyrrole-coated filters where static charges could cause the explosion of flammable solvents. Other important applications are related to military equipment, as radar-absorbing sheets. The microwave response of those fabrics seems to be ideal for camouflage nets that avoid visual, near-infrared and radar detection. Textile fabrics have also applications in fiber-reinforced composite structures of different resins. 

Another widely used approach is the in situ polymerization of an intractable polymer such as polypyrrole onto a polymer matrix with some degree of processibil-ity. Bjorklund [30] reported the formation of polypyrrole on methylcellulose and studied the kinetics of the in situ polymerization. Likewise, Gregory et al. [31] reported that conductive fabrics can be prepared by the in situ polymerization of either pyrrole or aniline onto textile substrates. The fabrics obtained by this process maintain the mechanical properties of the substrate and have reasonable surface conductivities. In situ polymerization of acetylene within swollen matrices such as polyethylene, polybutadiene, block copolymers of styrene and diene, and ethylene-propylene-diene terpolymers have also been investigated [32,33]. For example, when a stretched polyacetylene-polybutadiene composite prepared by this approach was iodine-doped, it had a conductivity of around 575 S/cm and excellent environmental stability due to the encapsulation of the ICP [34]. Likewise, composites of polypyrrole and polythiophene prepared by in situ polymerization in matrices such as poly(vinyl chloride), poly(vinyl alcohol), poly(vinylidine chloride-( o-trifluoroethylene), and brominated poly(vi-nyl carbazole) have also been reported. The conductivity of these composites can reach up to 60 S/cm when they are doped with appropriate species [10]. 

The range of surface resistance obtainable with conductive textiles based on polypyrrole or polyaniline (10-10,000 /2/D) allows these materials to be used for a number of applications. The use of such fabrics as reinforcements to polymeric resins results in composites that have interesting and well-controlled electrical properties. These unusual electrical properties are quite evident in the microwave region of the electromagnetic spectrum. The literature on microwave properties of such composites is not extensive, but some results have been reported by researchers in the United States, the United Kingdom, and France [68,71-74]. 

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