Du Pont Polymers

R. G. Peck, Ethylene jA.cry lie Elastomer—Meeting The Challenges of a DemandingMarket Bulletin EA-020.0185, Du Pont Polymers, Stow, Ohio, Jan. 24,... 

A. E. Hirsch and R. J. Boyce, Dynamic Properties of EthjlenefMcrylic Elastomers M New Heat Resistant Rubber Bulletin EA-530.604, Du Pont Polymers, Stow, Ohio, May 1977. 

J. W. Crary, Ethylene/Mery lie Elastomer—Basic Principles of Compounding and Processing, Bulletin EA-030.0482, Du Pont Polymers, Stow, Ohio, Apr. 1982. 

Information is presented in some detail on Du Pont Polymers proeess for reeovery of used polyesters from produets sueh as automotive bumpers. The process is reported to use a methanolysis teehnique and is reported to be able to separate pure monomer ingredients from reinforeed, painted or otherwise eontaminated polymers. DU PONT DE NEMOURS E.I., ... 

Environmental samples from munitions or swabs from environmental materials should be placed in sealed glass or Teflon (polytetrafluoroethylene, manufactured by Du Pont Polymers, Wilmington, Delaware) containers, and kept dry and as cold as possible. Caution Handling a dry or powdered toxin can be very dangerous because the toxin may adhere to skin and clothing and could be inhaled. 

Design Handbook for DuPont Engineering Polymers, Module 1, General Design Principles, Du Pont Polymers Ifechnical Bulletin 201742B, Wilmington, Del., 1992. 

Cyro Industries D S Plastics International Daicel Chemical Industries, Ltd. Dainippon Ink and Chemicals, Inc. DSM Engineering Plastics DSM Polymers International Du Pont Polymers Eastman Chemical Company Elf Atochem EMS-Chemie AG Emser Industries Ferro Corporation General Electric Plastics Himont Advanced Materials Himont Italia Hoechst AG... 

Materials similar ia high temperature properties to the Du Pont material with better low temperature properties have been synthesized usiag direct fluofination. The first was produced by reaction of fluorine with iaexpensive hydrocarbon polyethers such as poly(ethylene oxide). In the simplest case, poly(ethylene oxide) is converted to the perfluoroethylene oxide polymer ... 

The discovery of PTFE (1) in 1938 opened the commercial field of perfluoropolymers. Initial production of PTFE was directed toward the World War II effort, and commercial production was delayed by Du Pont until 1947. Commercial PTFE is manufactured by two different polymerization techniques that result in two different types of chemically identical polymer. Suspension polymerization produces a granular resin, and emulsion polymerization produces the coagulated dispersion that is often referred to as a fine powder or PTFE dispersion. 

Copolymeis of ethylene [74-85-1] and tetiafluoioethylene [116-14-3] (ETFE) have been alaboiatory curiosity for more than 40 years. These polymers were studied in connection with a search for a melt-fabricable PTFE resin (1 5) interest in them fell with the discovery of TFE—HFP (FEP) copolymers (6). In the 1960s, however, it became evident that a melt-fabricable fluorocarbon resin was needed with higher strength and stiffness than those of PTFE resins. Earlier studies indicated that TFE—ethylene copolymers [11939-51 -6] might have the right combination of properties. Subsequent research efforts (7) led to the introduction of modified ethylene—tetrafluoroethylene polymer [25038-71-5] (Tefzel) by E. I. du Pont de Nemours Co., Inc, in 1970. 

Ethylene and tetrafluoroethylene are copolymerized in aqueous, nonaqueous, or mixed medium with free-radical initiators. The polymer is isolated and converted into extmded cubes, powders, and beads, or a dispersion. This family of products is manufactured by Du Pont, Hoechst, Daikin, Asahi Glass, and Ausimont and sold under the trade names of Tefzel, Hostaflon ET, Neoflon EP, Aflon COP, and Halon ET, respectively. 

Applications. The applications sought for these polymers include composites, stmctural plastics, electronics/circuit boards, aircraft/spacecraft coatings, seals, dental and medical prosthetics, and laser window adhesives. However, other than the early commercialization by Du Pont of the NR-150 B material, Httie development has occurred. These polymers are quite expensive ( 110 to 2200 per kg for monomers alone). 

Solid Polymer E,kctroljte. The electrolyte in soHd polymer electrolyte (SPE) units is Nafion, a soHd polymer developed by Du Pont, which has sulfonic acid groups attached to the polymer backbone. Electrodes are deposited on each side of the polymer sheet. H" ions produced at the anode move across the polymer to the cathode, and produce hydrogen. The OH ions at the anode produce oxygen. These units have relatively low internal resistances and can operate at higher temperatures than conventional alkaline electrolysis units. SPE units are now offered commercially. 

Membrane modules have found extensive commercial appHcation in areas where medium purity hydrogen is required, as in ammonia purge streams (191). The first polymer membrane system was developed by Du Pont in the early 1970s. The membranes are typically made of aromatic polyaramide, polyimide, polysulfone, and cellulose acetate supported as spiral-wound hoUow-ftber modules (see Hollow-FIBERMEMBRANEs). 

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