Ethylene-propylene-diene-based

Ethylene—Propylene (Diene) Rubber. The age-resistant elastomers are based on polymer chains having a very low unsaturation, sufficient for sulfur vulcanization but low enough to reduce oxidative degradation. EPDM can be depicted by the following chain stmcture ... 

EPDM (Ethylene Propylene Diene Monomer Rubbers) 320 Steam, High-temperature Aqueous Solutions, Inorganic Acids and Organic Acids or bases... 

This is a nonpolar rubber with very little unsamration. Nanoclays as well as nanotubes have been used to prepare nanocomposites of ethylene-propylene-diene monomer (EPDM) rubber. The work mostly covers the preparation and characterization of these nanocomposites. Different processing conditions, morphology, and mechanical properties have been smdied [61-64]. Acharya et al. [61] have prepared and characterized the EPDM-based organo-nanoclay composites by X-ray diffracto-gram (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy... 

FIGURE 12.18 Stress-strain curves of rubber-fiber composites developed for solid rocket motor insulator A, ethylene-propylene-diene monomer (EPDM) rubber-carbon fiber composites B, EPDM mbber-melamine fiber composites C, EPDM mbber-aramid fiber composites and D, EPDM rubber-aramid pulp composites. 1 and 2 stands for unaged and aged composites respectively. Carbon fiber- and melamine fiber-reinforced composites contain resorcinol, hexamine, and silica in the concentrations 10, 6 and 15, respectively and aramid fiber- and aramid pulp-based composites contain resorcinol, hexamine, and silica in the concentrations 5, 3 and 15, respectively. (From Rajeev, R.S., Bhowmick, A.K., De, S.K., and John, B., Internal communication. Rubber Technology Center, Indian Institute of Technology, Kharagpur, India, 2002.)... 

Medintseva, T.I., Dreval, V.E., Erina, N.A., and Prut, E.V., Rheological properties thermoplastic elastomers based on isotactic polypropylene with an ethylene-propylene-diene terpolymer, Polym. Sci. A, 45, 2032, 2003. 

An oil-based drilling mud can be viscosified with maleated ethylene-propylene elastomers [919]. The elastomers are ethylene-propylene copolymers or ethylene-propylene-diene terpolymers. The maleated elastomers are far more effective oil mud viscosifiers than the organophilic clays used. On the other hand, specific organophilic clays can provide a drilling fluid composition less sensitive to high temperatures [491]. 

Let us recall also that vanadium-based soluble Ziegier-Natta catalysts have found widespread industrial application for the manufacture of elastomeric ethylene/propylene copolymers and ethylene/propylene/diene terpolymers [319-322]. The most commonly used vanadium-based catalysts for random ethylene/propylene copolymerisation are those prepared from VCI4, VOCI3, V(Acac)3, VO(OEt)Cl2, VO(OEt)2Cl or VO(OEt)3 as precursors and AlEt3, AlEt2Cl or Al(z-Bu)2Cl as activators, with an Al/V molar ratio not exceeding 3 1 [37, 72],... 

The elastomeric sealing components of the metering valve are particularly critical. In those valves used with CFC propellants, the elastomeric seals have typically been formed from an acrylonitrile/butadiene rubber, which has been cured with sulfur. These rubber seals may not be fully compatible with HFA propellants hence, alternative elastomeric materials have been used. These materials include peroxide-cured acrylonitrile/ butadiene, ethylene-propylene diene monomer (EPDM), and chloroprene and thermoplastic elastomers (TPE). The elastomeric materials used to form the dynamic seals around the stem and the static gasket seal between the can and valve may differ based on the required properties of the rubber for the specific function of the seal. The most important characteristics of the elastomeric seals... 

In addition to titanium-based Ziegler-Natta catalysts, vanadium-based systems have also been developed for PE and ethylene-based co-polymers, particularly ethylene-propylene-diene rubbers (EPDM). Homogeneous (soluble) vanadium catalysts produce relatively narrow molecular mass distribution PE, whereas supported V catalysts give broad molecular mass distribution.422 Polymerization activity is strongly enhanced by the use of a halogenated hydrocarbon as promoter in combination with a vanadium catalyst and aluminum alkyl co-catalyst.422,423... 

Arguably the most important amorphous ionomer is sulfonated polystyrene (SPS). Other ionomers include poly(styrene-rfln-methacrylic acid) (SMAA), polyurethanes, siloxanes, butadiene-based elastomers, ethylene-propylene-diene terpolymers, acrylates and methacrylates, polyphosphoesters, polyimides, and many others. ... 

EPDH (ethylene-propylene-diene) Use of halogen-based flame retardants in special products as well as possible exposure to neurotoxic n-hexane and carcinogenic benzene at production and processing. PS ... 

Reference 7 reviews a number of electron microscopy studies of ionomer morphology in the period up to 1979. None of these studies makes a convincing case for the direct imaging of ionic clusters. This is because of the small size of the clusters (less than 5 nm based on scattering studies) and difficulties encountered in sample preparation. The entire problem was reexamined in 1980(21). In this study ionomers based on ethylene-methacrylic acid copolymers, sulfonated polypentenamer, sulfonated polystyrene and sulfonated ethylene-propylene-diene rubber (EPDM) were examined. The transfer theory of imaging was used to interpret the results. Solvent casting was found to produce no useful information about ionic clusters, and microtomed sections showed no distinct domain structure even in ionomers neutralized with cesium. Microtomed sections of sulfonated EPDM, however,... 

These DEF systems are generally mounted on the side of the frame of the vehicle. The fill point is generally under hood. The actual diesel emissions fluid is a 35% urea-water mixture. Because this mixture freezes at -11°C, a heated EPDM (ethylene-propylene diene monomer)/nylon 6,6 line is used to deliver the urea from the tank to the exhaust stream. A sensor controls the flow of the urea to obtain the NOx reduction. This system can reduce NOx emissions by up to 40%. The urea refill rate is about once every 3 months based on typical driving schedules. 

Composition (type of polymeric components). The base polymer (which is to be modified) may be an amorphous polymer [e.g., polystyrene (PS), styrene-acrylonitrile copolymer, polycarbonate, or poly(vinyl chloride)], a semicrystalline polymer [e.g., polyamide (PA) or polypropylene (PP)], or a thermoset resin (e.g., epoxy resin). The modifier may be a rubber-like elastomer (e.g., polybutadiene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, or ethylene-propylene-diene copolymer), a core-shell modifier, or another polymer. Even smaller amounts of a compatibilizer, such as a copolymer, are sometimes added as a third component to control the morphology. 

The choice of date range is arbitrary. The number of journal articles for each year was obtained from a search of electronic version of English-based polymer and polymer-related journals using the keywords polyolefin and blends. Within polyolefin keyword, the subkeywords used in the search were polyethylene (PE, LLDPE, LDPE, HDPE, UHMWPE, PE, etc.), polypropylene (PP, iPP, sPP, aPP, etc.), polybutene-1, poly-4-methylpentene-l, ethylene-diene monomer, ethylene-propylene-diene terpolymer, ethylene propylene rubber, thermoplastic olefins, natural rubber (NR), polybutadiene, polyisobutylene (PIB), polyisoprene, and polyolefin elastomer. For the polyolefin blends patent search, polymer indexing codes and manual codes were used to search for the patents in Derwent World Patent Index based on the above keywords listed in the search strategy. 

We will now report the results of autohesion for homogeneous, symmetric joints of polyisoprene rubber (IR) and styrene-butadiene copolymer (SBR) both vulcanized by a sulfur-based system (Section 24.2.1), and of ethylene-propylene diene terpolymer (EPDM) crossHnked by an electron beam (Section 24.2.2). 

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