Polyethylene carbon black filled

Narkis M, Ram A and Flashner F (1978) Electrical properties of carbon black filled polyethylene, Polym Eng Set 18 649-653. 

Elongation was better retained also by the addition of 5% soot to LDPE. The material underwent a rapid erosslinking at 50-60 kGy whieh improved its elongation by a faetor of 4. At the same time, its tensile strength was decreased by 30%." Polyethylene eontaining earbon blaek was found to be resistant to ionizing radiation. The impact strength of carbon black filled HDPE and HDPE/EPDM was improved after exposure to Y-radiation. ... 

Feng, J. and Chan, C.M. (1998) Carbon black-filled immiscible blends of poly (vinylidene fluoride) and high density polyethylene electrical properties and morphology. Polym. Eng. Set., 38, 1649. 

Zhou and co-workers [28] measured the electrical conductivity/resistivity of carbon black filled linear low-density polyethylene (LLDPE) and blends of LLDPE with ethylene-methylacrylate (EMA). The percolation threshold of the blended polymer composite was significantly lower than that of the LLDPE composite, although in an EMA composite the threshold is higher. This effect was due to preferential absorption of the carbon black into the LLDPE due to phase separation and immiscibility in low-density polyethylene (LDPE)/EMA blends. The viscosity of polymers in the blend... 

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]. 

The results presented by Ling et al. [31], which are focused on carbon fibers as susceptors, describe a similar heating behavior like the one being observed with carbon black filled HDPE material. The work of John Harper [29] is related to the heating behavior of carbon black as a microwave susceptor in high density polyethylene by the modification of the surface area. The specific surface was varied from 7.5 to 137 m /g (Figure 2.14). 

Yin et al. [68] investigated the critical resistivity, dispersivity, and percolation threshold of low-density polyethylene carbon black. Li et al. [69] investigated the electrical properties and crystallization behavior of four different kinds of carbon black-filled polypropylene composites, prepared by the melt mixing method. All showed typical characteristics of percolation, but noticeably different percolation thresholds. When using carbon black with a higher structure, smaller particle diameter, and larger surface area, the composite showed better electrical conductivity and a lower percolation threshold. 

Lee JH, Kim SK, Kim NH (2006) Effects of the addition of multi-walled carbon nanotubes on the positive temperature coefficient characteristics of carbon-black-filled high-density polyethylene nanocomposites. Scripta Mater 55 1119-1122... 

J. Feng and C. M. Chan, Carbon Black-filled Immiscible Blends of Poly(vinylidene fluoride) and High Density Polyethylene Electrical Properties and Morphology, Polym. Eng. Sci. 38, 1649-1657 (1998). 

Zhang C, Ma C, Wang P, Sumita M. Temperature dependence of electrical resistivity for carbon black filled ultra-high molecular weight polyethylene composites prepared by hot compaction. Carbon 2005 43(12) 2544-53. 

Li Q, Kim JW, Shim TH, Jang YK, Lee JH. Positive temperature coefficient behaviour of the graphite nanofibre and carbon black filled high-density polyethylene hybrid composites. Adv Mater Res 2008 47 226-9. 

Hao Tang, Xingang Chen, and Yunxia Luo. Studies on the PTC/NTC effect of carbon black filled low density polyethylene composites. Europ. Polym. J. 33 (8), 1383-1386 (1997). 

Figure 1 shows how the viscosity of low density polyethylene-containing titanium dioxide changes as a function of apparent shear rate [18]. Similar results are shown in Fig. 2 for polystyrene filled with carbon black [19]. 

Fig.36. Variation in electrical conductivity (o) with molecular weight for polyethylene composites filled with 4% by volume carbon black, demonstrating the effects of orientation (I), degradation (II) and flow-induced segregation of carbon black aggregates (III). ( ) injection moulded (O) compression moulded (unoriented) [181]...

A carbon black addition above a percolation threshold of 5 vol% increases the conductivity until a plateau is reached at 20 vol%. " As the level increases above 10 vol%, the viscosity of the filled polypropylene increases rapidly (see Figure 9.9). As with polyethylene, carbon black is preferentially contained in one phase of a two phase blend."" This phenomenon is used in practice to lower the concentration of carbon black required for a certain level of conductivity. Here, again, carbon black is concentrated in the preferred location. Carbon black and copper powder were used to improve connectivity of YBaCuO in ceramic superconductors. "" Dispersion of copper particles and the related changes in conductivity were enhanced by the presence of acrylic acid modifier. ... 

A large diffusion may be found also for composite materials, carbon, or metal based. In the first case different types of polymeric resins (thermoplastics, such as polypropylene, polyethylene, and PVDF, or thermosettings, such as epoxies and phenolics) are filled with carbonaceous powders (graphite or carbon blacks), to provide a material characterized by very high chemical stability in the fuel cell environment and satisfactory properties of electrical conductivity, but which cannot offer sufficient robustness at thickness lower than 2 mm. The metal composite plates are essentially based on combinations (sandwiches of different layers) of stainless steel, porous graphite, and polycarbonates, with the aim to exploit the characteristics of different materials. Their fabrication can be more complex but this is compensated by the possibility to incorporate other functional components, such as manifolds, seals, and cooling layers. 

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