Carbon black nanocomposites, reinforced

Carbon black nanoparticle-reinforced polyisoprene applied in electric heating elements and resistors as thermodynamically inactive materials for a high dielectric constant (>1000) has been studied. The dissipation factor (tanS) of this carbon black nanocomposite was high (Xu and Wong, 2005). However, improving the dispersion of the nanoparticles in polymer lowers the percolation threshold of composites (Raza et al., 2012 Sumfleth et al., 2011). The electrical conductivity of rubbery epoxy/carbon black nanocomposites at 8 wt% filler loading was 2 x 10 S/m, which matched the criterion of electrical conductivity for electrostatic applications (10 S/m) (Ali Raza et al., 2012 Knite et al., 2004 Sasha Stankovich et al., 2006). 

Jeevananda T, Kim NH, Lee JH, Siddaramaiah B, Deepa Urs MV, Ranganathaiah C. Investigation of multi-walled carbon nanotube reinforced high-density polyethylene/carbon black nanocomposites using electrical DSC and positron lifetime spectroscopy techniques. Polym Int 2009 58 755-80. 

Recently, nanostructured carbon-based fillers such as Ceo [313,314], single-wall carbon nanotubes, carbon nanohorns (CNHs), carbon nanoballoons (CNBs), ketjenblack (KB), conductive grade and graphitized carbon black (CB) [184], graphene [348], and nanodiamonds [349] have been used to prepare PLA-based composites. These fillers enhance the crystalUza-tion ofPLLA [184,313,314].Nanocomposites incorporating fibrous MWCNTsandSWCNTs are discussed in the section on fibre-reinforced plastics (section 8.12.3). 

This is Volume 2 of Natural Rubber Materials and it covers natural rubber-based composites and nanocomposites in 27 chapters. It focuses on the different types of fillers, the filler matrix reinforcement mechanisms, manufacturing techniques, and applications of natural rubber-based composites and nanocomposites. The first 4 chapters deal with the present state of art and manufacturing methods of natural rubber materials. Two of these chapters explain the theory of reinforcement and the various reinforcing nanofillers in natural rubber. Chapters 5 to 19 detail the natural rubber composites and nanocomposites with various fillers sueh as siliea, glass fibre, metal oxides, carbon black, clay, POSS and natural fibres ete. Chapters 20-26 discuss the major characterisation techniques and the final ehapter covers the applications of natural rubber composites and nanoeomposites. By covering recent developments as well as the future uses of rubber, this volume will be a standard reference for scientists and researchers in the field of polymer chemistry for many years to come. 

Carbon black (CB) is indisputably the most widely used reinforcing filler in NR formulations. It improves tensile and tear strengths, modulus and hardness, abrasion and thermo-oxidative resistance, etc. of NR-based materials. CB is manufactured by a variety of processes, including the channel process, to produce furnace black, thermal black, lamp black and acetylene black. NR-based composites and nanocomposites with the addition of CB exhibit the monotonous black colour to the finished goods. 

NR composites and nanocomposites can be fabricated by three main techniques, namely latex compounding, solution mixing and melt blending. A variety of nanofillers, such as carbon black, silica, carbon nanotubes, graphene, calcium carbonate, organomodified clay, reclaimed rubber powder, recycled poly(ethylene terephthalate) powder, cellulose whiskers, starch nanocrystals, etc. have been used to reinforce NR composites and nanocomposites over the past two decades. In this chapter, we discuss the preparation and properties of NR composites and nanocomposites from the viewpoint of nanofillers. We divide nanofillers into four different types conventional fillers, natural fillers, metal or compound fillers and hybrid fillers, and the following discussion is based on this classification. 

Another key factor in governing the reinforcement efficiency of filler is its surface area. Ideally, the dispersion of silica in NR-silica composite should be as homogeneous as possible and less silica-silica interaction. This chapter will focus on NR-silica nanocomposites obtained through various approaches as reported in the literature. It is worth noting that from the aspect of sustainable development, NR-silica nanocomposite provides the opportunity for greener products where carbon black is either totally or partially replaced by silica. 

The addition of nanoparticles to synthetic mbber resulting in enhancement in thermal, stiffness and resistance to fracture is one of the most important phenomena in material science technology. Thermal and mechanical properties of clays mul-tiwalled carbon nanotubes reinforced ethylene vinyl acetate (EVA) prepared through melt blending showed synergistic effect in properties [86]. Malas et al. reported (SBR/BR)/expanded graphite (EG) and black carbon (CB) nanocomposites by melt blending, this study demonstrated that the presence of EG improvement thermo-mechanical properties and the presence of CB are a factor important to... 

The words nanocomposites and nanofillers are fairly recent, but have been in use since 1904 for example, carbon black is being used as a reinforcing filler in rubbers and apparently always existed in nature (in minerals and vegetation) [1, 2]. 

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]. 

Kalavtjidou et al. [74] measured the mechanical and electrical properties of poly-propylene-based nanocomposites reinforced with up to 25 vol% exfoliated graphite nanoplatelets. The mechanical and electrical properties of the graphite nanocomposites were investigated and compared to the properties of polypropylene-based composites reinforced with other conductive materials, for example, carbon black and carbon fibers. It was found that the graphite nanoplatelets were the most effective at increasing the modulus of the polypropylene and comparable to the other materials in terms of percolation threshold. 

In spite of its great fundamental interest and commercial importance, one of the most important unsolved problems in the aiea of elastomers and rubberlike elasticity is the lack of a good molecular understanding of the reinforcement provided by fillers such as carbon black and silica [1-5]. More specifically, the reinforcement of elastomers is an interesting aspect in the basic research of nanocomposites in general, and is of much practical importance since the improvements in properties fillers provide are critically important with regard to the utilization of elastomers in almost all commercially significant applications. Some of the work on this problem has involved analytical theory [6-12], but most of it is based on a variety of computer simulations [13-46]. 

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