U.S. Patent 7,645,318 (Jan. 12, 2010), "Producing Nanoparticles Using Nanoscale Polymer Templates," Darren Anderson, Jose Amado Dinglasan, and Nikolai Loukine (Vive Nano, Inc., Toronto, Ontario, Canada).
Multicomponent nanoparticles add "something special" to nanocomposites because of their unique properties from two or more components. Anderson et al. have developed a template method for producing inorganic nanoparticles encased in a polyelectrolyte. A polymer template is used to encapsulate precursor groups, forming oxide/hydroxide cores. The polymer template, such as poly N isopropylacrylamide, is crosslinked to maintain its shape during nanoparticle synthesis. The polymer template is a soluble polyelectrolyte with functional groups that can link to the precursor molecules. The nanoparticle precursor is an organic salt, inorganic salt, or complex salt.
U.S. Patent 7,622,153 (Nov. 24, 2009), "Method of Making Vapor Deposited Oxygen-Scavenging Particles," Kevin L. Rollick (M&G USA Corp., Apple Grove, West Virginia, USA).
Oxygen scavengers are often used to reduce oxygen content within food packaging. The scavengers can be introduced into the package or be part of the package wall, forming an active barrier. Rollick has developed an oxygen-scavenging system, consisting of an activator and an oxidizer, that forms an active barrier. The activator is a protic hydrolysable halogen compound, and the oxygen-scavenging particle is a reduced metal. A typical activator is titanium tetrachloride, and the typical oxidizer is elemental iron deposited by decomposition of carbonyl iron vapor. It is preferable that the activating component initiate the reaction of the oxidizable component in the presence of water.
U.S. Patent 7,622,527 (November 24, 2009), "Polymeric Material Having Polyrotaxane and Process for Producing the Same," Kohzo Ito and Masatoshi Kidowaki (University of Tokyo, Bunkyo-ku, Tokyo, Japan).
Highly crosslinked materials such as contact lenses, paints, and varnishes are often brittle because of nonuniform crosslinking, which leads to internal stresses and cracking. Ito and Masatoshi developed a thermoset consisting of a polyrotaxane and a thermoset. Polyrotaxanes are polymers with cyclic groups threaded onto a polymer chain. The polymer chain can move freely through the cyclic ring. The linear chain is capped at each end to prevent dissociation. This free motion within the thermoset permits relaxation of strained segments and eliminates internal stresses. This relaxation capability, also, increases toughness and impact strength.
Bumpers and Fenders
U.S. Patent 7,624,694 (Dec. 1, 2009), "Resilient Device," Karl L. Aschenbach (Tacoma, Washington, USA).
Bumpers and fenders prevent damage when boats bump against pilings or docks. Fenders are typically attached to boat hulls or to docks, pilings, seawalls, bridge footings, and other structures. Aschenbach has developed a resilient bumper based on a mounting connected to a resilient leaf spring. The leaf spring collapses and absorbs a substantial amount of energy on impact while the free end slides along the mounting. This leaf spring is an extruded high-strength abrasion-resistant plastic with a low coefficient of friction, such as ultrahigh-molecular-weight polyethylene.
U.S. Patent 7,626,061 (Dec. 1, 2009), "Method and Apparatus for Continuous Decomposing Waste Polymeric Materials," Leonid Datsevich, Jorg Gerchau, Frank Gorsch, and Ralph Wolfrum (MPCP GmbH, Bayreuth, Germany).
Datsevich et al. have developed a method for recycling hydrocarbon-containing plastic and rubber waste, including polyurethane and scrap tires, by pyrolysis of a moving stream of shredded material through a tubular reactor. The shredded wastes are heated at atmospheric pressure in air to the decomposition temperature from 300[degrees]C to 650[degrees]C. The vapors are condensed and converted to usable products. The resulting char forms carbon black, which is useful as a filler. Part of the heat for the reaction is generated by partial oxidation of the reaction mixture, reducing energy requirements. The reactor is a simple tube with a relatively small volume.
U.S. Patent 7,629,424 (Dec. 8, 2009), "Metal-Containing Compositions and Method of Making Same," Mangala Malik and Joseph J Schwab (Pryog, LLC, Providence, Rhode Island, USA).
Polymeric films with refractive indices of at least 1.5 are needed for optical applications. Malik and Schwab have developed films containing a metal precursor, a prepolymer, and a catalyst or initiator. Both components may contain additional functional groups for compatibility and clarity. These metallic compositions can be used to produce films with 90% transmittance and a refractive index of 1.5 to 1.8 in the 400-700 nm range of light and 1.5 to 2.4 in the 150-400 nm range. An example of a metal precursor is zirconium 6-(2-naphthylthio) bicyclo[2.2.1] heptane-2-carboxylate triacrylate, and an example of a prepolymer is diurethane dimethacrylate.
Reducing Melt Fracture
U.S. Patent 7,632,086 (Dec. 15, 2009), "Melt Fracture Reduction," Thomas Redden Veariel, Costas George Gogos, David Burton Todd, and Bainian Qian (ExxonMobil Chemical Patents Inc., Houston, Texas, USA).
Many resins, such as polyethylene, are susceptible to extrudate distortion and surface roughness such as "sharkskin" at high extrusion velocities. This surface melt fracture occurs in pelletizing, sheeting, and blown film lines. Veariel et al. have reduced this melt fracture, without special additives, by heating the die near the exit. The required surface temperatures are 30 to 170 Celsius degrees above the bulk temperature of the extruded product. They were able to achieve three times the normal flow rate possible for polyethylene resins without melt fracture.
U.S. Patent 7,635,725 (Dec. 22, 2009), "Crosslinked Polymers," Anuj Bellare and Thomas S. Thornhill (The Brigham and Women's Hospital, Inc., Boston, Massachusetts, USA).
High-energy radiation such as gamma, X-ray, or electron beam radiation is preferred for sterilization of some medical devices because the radiation also crosslinks the material and improves wear resistance. However, high-energy radiation may generate long-lived reactive species within the matrix, such as free radicals, which, over time, react with oxygen and degrade the material. Bellare and Thornhill improved stability of crosslinked ultrahigh-molecular-weight polyethylene (UHMWPE) by heating the uncrosslinked material above the malting point, cooling, and then irradiating the material for sterilization and crosslinking. After crosslinking, the material is compressed and reheated below the melting temperature. The result is a highly crystalline, oxidation-resistant crosslinked UHMWPE material without residual free radicals.
U.S. Patent 7,632,406 (Dec. 15, 2009), "Smart Membranes for Nitrate Removal, Water Purification, and Sdective Ion Transportation," William D. Wilson, Charlene M. Schaldach, William L. Bourcier, and Phillip H. Paul (Lawrence Livermore National Security, LLC, Livermore, California, USA).
Ultrafiltration membranes are used to remove colloid-sized impurities during water purification. Because of their larger pores, they permit a high flow rate than nanofiltration and reverseosmosis membranes, but there is a limit to their effectiveness with minute substances, such as bacteria and, especially, dissolved ions. Wilson et al. have developed a microengineered porous ultrafiltration membrane based on porosity and electrostatic charging. When the fluid contacts the membrane, the pores become charged, allowing passage of oppositely charged ions only. These membranes can remove nitrates as well as bacteria and be generally more effective in water purification and selective ion transportation. The smart-membrane system includes a cathode, an anion-permeable membrane with a positive surface charge, a cation-permeable membrane with a negative surface charge, an anode, and a voltage source.
Roger D. Corneliussen is Professor Emeritus of Materials Engineering, Drexel University, in Philadelphia, Pennsylvania, USA. He is editor of Maro Polymer Alerts and the Maro Polymer website (www. maropolymeronline, com). He has been active in SPE since 1962 and has served on the board of the Philadelphia Section and as SPE Councilor. For Maro Patent Alerts, he reviews all U.S. Patents weekly, makes links to the polymer-related patents, and sends the links daily to subscribers. These patent abstracts are based on the weekly selection process. To sample Maro Patent Alerts, email a request to email@example.com.
The patents described here are selected on the basis of their novelty; selection does not affirm or imply the accuracy of a patent or its practical applicability.
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|Author:||Corneliussen, Roger D.|
|Date:||Apr 1, 2010|
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