Polyethylene oxide, carbon nanotube

In the last decade, considerable progress was observed in the field of PO/compatibil-izer (predominantly on the base of PO-g-MA)/organo-surface-modified clay nanocomposites. Polyethylene (PE), polypropylene (PP), and ethylene-propylene (EP) rubber are one of the most widely used POs as matrix polymers in the preparation of nanocomposites [3,4,6,30-52]. The PO silicate/silica (other clay minerals, metal oxides, carbon nanotubes, or other nanoparticles) nanocomposite and nanohybrid materials, prepared using intercalation/exfoliation of functionalized polymers in situ processing and reactive extrusion systems, have attracted the interest of many academic and industrial researchers because they frequently exhibit unexpected hybrid properties synergisti-cally derived from the two components [9,12,38-43]. One of most promising composite systems are nanocomposites based on organic polymers (thermoplastics and thermosets). 

Goh HW, Goh SH, Xu GQ, Lee KY, Yang GY, Lee YW, Zhang WD (2003). Optical limiting properties of double-C60-end-capped poly(ethylene oxide), double-C -end-capped polyethylene oxide)/poly(ethylene oxide) blend, and double-C -end-capped poly(ethylene oxide)/multiwalled carbon nanotube composite. J. Phys. Chem. B 107 6056-6062. 

As with fullerenes, carbon nanotubes are also hydrophobic and must be made soluble for suspension in aqueous media. Nanotubes are commonly functionalized to make them water soluble although they can also be non-covalently wrapped with polymers, polysaccharides, surfactants, and DNA to aid in solubilization (Casey et al., 2005 Kam et al., 2005 Sinani et al., 2005 Torti et al., 2007). Functionalization usually begins by formation of carboxylic acid groups on the exterior of the nanotubes by oxidative treatments such as sonication in acids, followed by secondary chemical reactions to attach functional molecules to the carboxyl groups. For example, polyethylene glycol has been attached to SWNT to aid in solubility (Zhao et al., 2005). DNA has also been added onto SWNT for efficient delivery into cells (Kam et al., 2005). 

Shaheer Akhtar, M., Park, J. G., Lee, H. C., Lee, S. K., Yang, 0. B. (2010). Carbon nanotubes-polyethylene oxide composite electrolyte for solid-state dye-sensitized solar cells, Electrochim. Acta. 55(7), 2418-2423. 

Uddin, N. M., Capaldi, F. M., Farouk, B. (2011). Molecular dynamics simulations of the interactions and dispersion of carbon nanotubes in polyethylene oxide/water systems. Polymer. 52(2), 288-296. 

Hydroxyapatite (CajQ(P04)g(0H)2) has also attracted considerable interest as a catalyst support. In these materials, wherein Ca sites are surrounded by P04 tetrahedra, the introduction of transition metal cations such as Pd into the apatite framework can generate stable monomeric phosphate complexes that are efficient for aerobic selox catalysis [99]. Carbon-derived supports have also been utihzed for this chemistry, and are particularly interesting because of the ease of precious metal recovery from spent catalysts simply by combustion of the support. Carbon nanotubes (CNTs) have received considerable attention in this latter regard because of their superior gas adsorption capacity. Palladium nanoparticles anchored on multiwalled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) show better selectivity and activity for aerobic selox of benzyl and cinnamyl alcohols [100, 101] compared to activated carbon. Interestingly, Pd supported on MWCNTs showed higher selectivity toward benzaldehyde, whereas activated carbon was found to be a better support in cinnamyl alcohol oxidation. Functionalized polyethylene glycol (PEG) has also been employed successfully as a water-soluble, low-cost, recoverable, non-toxic, and non-volatile support with which to anchor nanoparticulate Pd for selox catalysis of benzyl/cinnamyl alcohols and 2-octanol [102-104]. 

BR, butyl rubber CB, carbon black CBS, cyclohexyl-2-benzothiazolefulfenamide CNT, carbon nanotube CSPE, chlorosulfonate polyethylene CIP, carbonyl-iron powder EPM, ethylene propylene monomer EPDM, ethylene propylene diene monomer EVA, ethylene-vinyl acetate FSR, fluorosilane rubber GRP, graphite powder HGM, hollow glass microsphere lONP, iron oxide nanoparticle LDH, layered double hydroxide MBT, 2-mercaptobenzothiazol MMT, modified montmorillonite NR, natural rubber PAMAM, polyamidoamine R-EPDM, recycled ethylene propylene diene monomer SR, silicon rubber SBR, styrene-butadiene rubber TBBS, iV-tert-butyl-2-benzothiazolesulfenamide. 

Carbon nanotubes are being increasingly used for the reinforcement of plastics, including epoxy resins [57-59], polyamides [55, 60-62], polyimides [63], poly-silsesquioxane [64], polycaprolactam [65], polyethylene oxide [66], polyethylene [67, 55,62], polyurethane [67], ethylene-vinyl acetate [69-73], polyhydroxybutylene-co-hydroxyvalerate [75], ethylene-propylene diene terpolymer [73], and sulfonated polyarylene sulfone [53]. 

In the UK, researchers at Cambridge University have devised a method of growing vertical carbon nanotubes on a flexible plastic substrate which gives scope for further research into potential applications especially where flexibility is a key element of the product design. At Sheffield University the research project involves the dispersion of nano-sized droplets of PEDOT (or other conducting polymers) into a polyethylene oxide polymer electrolyte matrix. Together with a suitable redox couple, where oxidation and reduction are considered together as complementary processes, it is possible to produce efficient, switchable windows for microwaves. 

Stobinski L, Lesiak B, Kover L, Toth J, Biniak S, Trykowski G, Judek J (2010) Multiwall carbon nanotubes purification and oxidation by nitric acid studied by the FTIR and electron spectroscopy methods. J Alloy Compd 501 77-84 Sudesh K, Abe H, Doi Y (2000) Synthesis, structure and properties of polyhydroxyalkanoates biological polyesters. Prog Polym Sci 25 1503-1555 Tang W, Santare MH, Advani SG (2003) Melt processing and mechanical property characterization of multi-walled carbon nanotube/high density polyethylene (MWNT/HDPE) composite films. Carbon 41 2779-2785... 

Additives used in final products Fillers carbon nanotubes, fumed silica, graphite. Fillers molybdenum disulfide, montmorlllonite, nanosilica, titanium dioxide, vanadium oxide Plasticizers dioctyl phthalate, ethylene carbonate, polyoxyethylene-sorbitane monolaureate, propylene carbonate, polyethylene and polypropylene glycols, tetraethylene glycol, tetraglyme Antislatics polyoxyethylene sorbitan monolaurate, polyoxyethylene glycol, polyoxyethylene octylphenyl ether ... 

Additives used in finai products Fillers aluminum nitride, barium titanate, aluminum nitride, antimony trioxide, aramide fiber, attapulgite, carbon fiber, carbon nanofiber, carbon nanotubes, clay, glass fiber, graphite, molybdenum sulfide, montmorillonite, PTFE, silica, smectite, titanium oxide whisker Plasticizers diethylene glycol dibenzoate, dimethyl phthalate, triallyl phthalate, diethynyldi-phenyl methane, phenylethynyidiphenyl methane, 4-hydroxy-benzophenone Antistatics antimony-containing tin oxide, carbon black, carbon, nanotubes, indium oxide microspheres, polythiophene Release polyethylen wax, PTFE, silicone oil, zirconium chelate ... 

Zheng X, Xu Q. Comparison study of morphology and crystallization behavior of polyethylene and poly (ethylene oxide) on single-walled carbon nanotubes. J Phys Chem B 2010 114 9435-9444. 

Bocchini S, Frache A, Camino G, Claes M. Polyethylene thermal oxidative stabilisation in carbon nanotubes based nanocomposites. Eur Polym J 2007 43 3222-3235. 

Dintcheva, N.T., La Mantia, F.P., Malatesta, V. Photo-oxidation behaviour of polyethylene/multi-wall carbon nanotube composite films. Polym. Degrad. Stab. 94, 162-... 

Kim rr, Lee JH, Shofner ML, Jacob K, Tannenbaum R. Crystallization kinetics and anisotropic properties of polyethylene oxide/magnetic carbon nanotubes composites films. Polymer 2012 53 2402-11. 

The chapter deals with a brief account of various topics in polyethylene-based blends, composites and nanocomposites. We discuss the different topics such as ultra high molecular weight polyethylene (UHMWPE) for orthopaedics devices, stabilization of irradiated polyethylene by the introduction of antioxidants, polyethylene-based conducting polymer blends and composites, polyethylene composites with hgnocellulosic material, LDH as nanofillers of nanocomposite materials based on polyethylene, ultra high molecular weight polyethylene and its reinforcement/oxidative stability with carbon nanotubes in medical devices, montmorillonite polyethylene nanocomposites, and characterization methods for polyethylene based composites and nanocomposites. 

Ultra High Molecular Weight Polyethylene and its Reinforcement/Oxidative Stability with Carbon Nanotubes in Medical Devices... 

N. H. Kim, T. Kuila and J. H. Lee, Enhanced mechanical properties of a multiwall carbon nanotube attached pre-stitched graphene oxide filled linear low density polyethylene composite. /. Mater. Chem. A. 2, 2681-2689 (2014). 

Keywords Ultra high molecular weight polyethylene, arthroplasty, orthopedic implants, biocompatibility, wear, oxidation, irradiation, cross-linking, viscoelastic, viscoplastic, carbon nanotubes... 

THE EFFECT OF CARBON NANOTUBES ON THE CRYSTALLIZATION BEHAVIOR OF POLYETHYLENE OXIDE... 

The effect of well-dispersed carbon nanotubes on the ciystalhzation characteristics of polyethylene-oxide was studied. The specimens were prepared via the solution-sonication procedure. The results confirm the effectiveness of CNTs as nucleation agents for semi-ciystalline polymers. 

Polyethylene Oxide (in a powder form) of molecular weight around 600000 (POLYOX WSR 205), was supplied by Dow Chettucals Multi-Walled Carbon Nanotubes (MWNTs), purchased from Cheap Tubes Inc., were said to be of 95 wt% purity with outside diameter 20-30 mn and length 10-30 pm. 

---