Plastics Engineering - May 2014 - (Page 60)

Industry PAtEnts Medical joint replacement is expanding in an aging population. Ultra-high molecular weight polyethylene (UHMWPE) is the material of choice because of its toughness, low friction, and exceptional abrasion resistance. However, processing remains difficult because it does not become fluid, only rubbery, when heated above its crystalline melting point (138-142° c). Van citters developed angular extrusion, a solid state process, for forming these materials, resulting in high crystallinity by small crystallite size. He forced cold UHMWPE powders into a channel past barriers to form a shaped, solid structure. Carbon nanotube touch Panels U.s. Patent 8,642,895 (February 4, 2014), "substrate with transparent conductive layer and Method for Producing the same, and touch Panel Using the same," Junji Mata, Jun tsukamoto, and Hiroki sekiguchi (toray industries, inc., Japan). touch panels are based on laminates of clear, conductive, and insulating layers. adhesion between the layers is critically important, since a touch panel consists of a substrate with a transparent conductive layer requiring good adhesion and in-plane uniformity. Mata, tsukamoto, and sekiguchi developed a touch panel with a transparent support, a thermosetting adhesive containing 50 wt% melamine/ formaldehyde resin, and a carbon nanotube (cnt) layer. the cnt layer can consist of single-walled, double-walled, triple-walled, or higher multiwalled cnts with diameters ranging from 0.3 to100 60 nm and lengths from 0.1 to 20 microns. this conductive layer is formed by coating with a cnt water dispersion the substrate previously coated with the melamine adhesive. Chlorine Biodegradation U.s. Patent 8,647,824 (February 11, 2014), "Microbial reductive Dehalogenation of Vinyl chloride," alfred M. spormann, Jochen a. Muller, Bettina M. rosner, gregory Von abendroth, galit Meshulam-simon, and Perry l. Mccarty (toray industries, inc., Japan, and leland stanford Junior University, Palo alto, california, Usa). One serious environmental problem is the contamination of groundwater with chlorinated solvents, as well as with degradation products of chlorinated polymers such as polyvinyl chloride, including chlorinated additives. groundwater remediation costs millions. One such strategy, the removal of these contaminants by naturally occurring chloroethene-degrading microorganisms (bioremediation), appears to be a viable and cost-effective method. spormann et al. developed bacteria for the bioremediation of chlorinated materials based on Dehalococcoides-like organisms. they isolated a strain of Dehalococcoides bacteria that metabolizes vinyl chloride. reductase nucleic acids and their encoded polypeptide were isolated and identified. these reductases are catalysts for the metabolism of vinyl chloride. in addition, they can be an indicator of the metabolic capabilities of microorganisms for the screening and research of organism dehalogenation. nanocomposite Holograms U.s. Patent 8,647,794 (February 11, 2014), "Method of Forming Holograms in Polymer composites with confined crystallization," Patrick Joseph Mccloskey, amitabh Bansal, and Warren William reilly (general Electric company, niskayuna, new York, Usa). Optically clear plastics with confined crystallization can be used for holographic data storage. However, a commercially viable material has yet to be developed. Mccloskey, Bansal, and reilly developed a polymer composite consisting of a polymer matrix filled with 15 to 30 wt% 200-nm nanoparticles. candidate glassy, amorphous polymers include polystyrenes, acrylics, polycarbonates, polyesters, polyethers, epoxies and their copolymers. suitable crystallizable polymers include polyethylene glycol (PEg), nylon, polyalkenes, polybutylterephthalates, polyethylene terepthalates, polyvinyl acetates, polyvinyl chlorides, polyphenyl sulfones, and polycaprolactones. For holographic data storage applications, the composite morphology after microphase separation should remain unchanged during melting and recrystallization of the dispersed particles. this composite also contains a light-absorbing chromophores which absorb light from the interference pattern, creating localized hot spots. in one example, Ps-PMMa resins were blended with PEg and phthalocyanine dyes, and then molded into disks for holographic recording. | Plastics EnginEEring | MaY 2014 | www.4spe.org | www.plasticsengineering.org http://www.4spe.org http://www.plasticsengineering.org

Plastics Engineering - May 2014

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