Epoxy resins carbon black reinforcement

Electrical conductivity measurements have been reported on a wide range of polymers including carbon nanofibre reinforced HOPE [52], carbon black filled LDPE-ethylene methyl acrylate composites [28], carbon black filled HDPE [53], carbon black reinforced PP [27], talc filled PP [54], copper particle modified epoxy resins [55], epoxy and epoxy-haematite nanorod composites [56], polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) blends [57], polyacrylonitrile based carbon fibre/PC composites [58], PC/MnCli composite films [59], titanocene polyester derivatives of terephthalic acid [60], lithium trifluoromethane sulfonamide doped PS-block-polyethylene oxide (PEO) copolymers [61], boron containing PVA derived ceramic organic semiconductors [62], sodium lanthanum tetrafluoride complexed with PEO [63], PC, acrylonitrile butadiene [64], blends of polyethylene dioxythiophene/ polystyrene sulfonate, PVC and PEO [65], EVA copolymer/carbon fibre conductive composites [66], carbon nanofibre modified thermotropic liquid crystalline polymers [67], PPY [68], PPY/PP/montmorillonite composites [69], carbon fibre reinforced PDMS-PPY composites [29], PANI [70], epoxy resin/PANI dodecylbenzene sulfonic acid blends [71], PANI/PA 6,6 composites [72], carbon fibre EVA composites [66], HDPE carbon fibre nanocomposites [52] and PPS [73]. 

Kim et al. [56] also discussed the cryogenic properties at -150°C of carbon black nanoparticle-reinforced epoxy resins. Nanoparticle reinforcement improved fracture toughness at room temperature but decreased fracture toughness at cryogenic temperatures. 

Organic matrices are divided into thermosets and thermoplastics. The main thermoset matrices are polyesters, epoxies, phenolics, and polyimides, polyesters being the most widely used in commercial applications (3,4). Epoxy and polyimide resins are applied in advanced composites for structural aerospace applications (1,5). Thermoplastics Uke polyolefins, nylons, and polyesters are reinforced with short fibers (3). They are known as traditional polymeric matrices. Advanced thermoplastic polymeric matrices like poly(ether ketones) and polysulfones have a higher service temperature than the traditional ones (1,6). They have service properties similar to those of thermoset matrices and are reinforced with continuous fibers. Of course, composites reinforced with discontinuous fibers have weaker mechanical properties than those with continuous fibers. Elastomers are generally reinforced by the addition of carbon black or silica. Although they are reinforced polymers, traditionally they are studied separately due to their singular properties (see Chap. 3). 

The DC properties of anti-static epoxy GFR pipes The use of glass-fibre reinforced (GFR) epoxy resin pipes is, especially in tankers, hampered by the bad electrostatic properties of these pipes. The possibility to decrease the volume resistivity to an acceptable level using only a small amount of carbon black (see 5.3.2) resulted in the development of the WAVIMAR anti-static GFR pipe system by Wavin BV. This pipe system is based on a liquid DGEBA/MDA (100/27) and cured for two hours at 120°C, containing about 1.5 %wt. (on the resin phase) of Ketjen black EC-2000 carbon black. The specific volume resistivity of a sample of such a pipe was measured as a function of the direction, the field strength and the pipe wall thickness. 

Volnme resistivities have been reported on phenol-formaldehyde [37], carbon fibre reinforced ABS terpolymer [35], natural rubber [38], polystyrene (PS) [35], HDPE-natnral fibre composites [34], carbon black filled PP-epoxy-glass fibre composites [5], XLPE [32], nanoclay reinforced EPDM-g-TMEVS [31] and epoxy resin/PANI blends [33]. 

Fig. 5.66 Reflected light micrograph of polished carbon fiber composites are shown fibers are white, voids (holes) are black, and the resin is gray in color due to surface reflectivity. A section of a graphite fiber reinforced composite (A) shows a complex arrangement of fibers with uniform wetting and packing. Single ply carbon fiber panels (B) embedded in epoxy and polished are uniformly packed. Higher magnification micrographs show detail is possible by this technique for fibers oriented parallel (C) and perpendicular (D) to the polished surface.

Organic-ceramic composites may use an epoxy as the matrix and glass or ceramic powder as the filler. A common example is the fiberglass-reinforced epoxy used as a printed circuit laminate. An epoxy substrate filled with alumina and carbon black has also been developed. By weight, the composition is 10.8 percent epoxy resin, 89 percent alumina, and 0.2 percent carbon black. This material has a thermal conductivity of 3.0 to 4.0 W/(m K), compared to both glass-epoxy printed circuit material [0.2 W/(m K)] and glass-alumina low temperature cofired substrates [2.5 W/(m K)]. The TCE (17 ppm/°C) is substantially below that... 

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