Ethylene-propylene-diene-based rubbers

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

Examples of vulcanizable elastomers include natural rubber (NR), styrene butadiene rubber (SBR), butadiene rubber (BR), ethylene-propylene-diene monomer-rubber (EPDM), butyl rubber (HR), polychloroprene or neoprene (CR), epichlorohydrin rubber (ECO), polyacrylate rubber (ACM), millable polyurethane rubber, silicone rubber, and flu-oroelastomers. Examples of thermoplastic elastomers include thermoplastic polyurethane elastomers, styrenic thermoplastic elastomers, polyolefin-based thermoplastic elastomers, thermoplastic polyether-ester (copolyester) elastomers, and thermoplastic elastomers based on polyamides. 

Rubbers (or elastomers) are used mainly as floor coverings and membranes. Rubber flooring containing chlorine-based ingredients are not recommended because of the hazards involved. However, in most cases it is not true for other rubber types ethylene propylene diene (EPDM) rubber is recommended by the Danish Environmental Protection Agency as an alternative to PVC. 

Chakraborty S, Sahoo N G, Jana G K and Das C K (2004) Self-reinforcing elastomer composites based on ethylene-propylene-diene monomer rubber and liquid-crystalline polymer, J Appl Polym Sa 93 711-718. 

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 ... 

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.)... 

Other aldehydes used for the synthesis of phenolic polycondensates include butyraldehyde, furfural or chloral. Efficient AO, e.g. polycondensate 129, were prepared with sulfur containing aldehydes [161]. Linear polycondensates of phenols and aldehydes were tested as AO in mineral oils, PE, PP, poly (ethylene-co-propylene), PS, PA and/or diene based rubbers [159, 162]. Cyclic phenolic condensates, calixarenes (130) posses interesting properties. Calixarenes were synthesized from 4-acyl-, 4-methyl-, 4-tm-butyl- or 4-phenylphenol in alkaline catalysed processes. Cycles containing 4 to 7 phenolic units were formed and tested as AO in PE or PP [163,164], Nickel(II) salt of 130 (R = lerf-butyl, n = 1)... 

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... 

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,... 

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). 

During the last several years, much effort has been spent on developing new materials, based on iPP/elastomers blends. This interest is related to the fact that addition of the rubber phase improves the impact strength of the iPP, The present paper reports on a study of the isothermal crystallization and melting behaviour of thin films of isotactic polypropylene blended with an ethylene--propylene diene terpolymer and three samples of polyisobutylene with different molecular mass. 

Ethylene-propylene rubber is a synthetic hydrocarbon-based rubber made either from ethylene-propylene diene monomer or ethylene-propylene terpolymer. These monomers are combined in such a manner as to produce an elastomer with a completely saturated backbone and pendant unsaturation for sulfur vulcanization. As a result of this configuration, vulcanizates of EPDM elastomers are extremely resistant to attack by ozone, oxygen, and weather. 

Competition between NR and bio-based SR (SR made from biosourced feedstock) should not be underestimated. For example in 2012, LANXESS is planning to produce the world s first SR, i.e. ethylene propylene diene monomer (EPDM) rubber (under the brand name of Keltan Eco) from ethylene derived from sugar cane at its Triunfo plant in Brazil. The ethanol is dehydrated into ethylene and polymerized to produce EPDM rubber." Besides, bio-based SR is suggested to be the bio-based feedstock of poly(butadiene) rubber for tyre industries. 

Use of nanoparticles as fillers in mbbers is highly relevant because end use applications of rubber compounds require filler reinforcement. Most of the literature on rubber nanocomposites is based on the use of nanoclay as the filler. It has been shown that incorporation of nanoclay in synthetic rubbers, like styrene butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), ethylene propylene diene monomer (EPDM) mbber etc. enhances the mechanical, anti-ageing and barrier properties. 

T. Chatteijee, P. Dey, G.B. Nando, K. Naskar, Thermo-responsive shape memory polymer blends based on alpha olehn and ethylene propylene diene rubber, Polymer, ISSN 0032-3861 (2015). AvaUable online 9 October 2015. http //dx.doi.0rg/lO.lOl6/j. polymer.2015.10.007. 

Unlike natural rubber, filled synthetic rubber compounds (e.g., styrene butadiene rubber (SBR), ethylene propylene diene rubber (EPDM)) exhibit inherent low tack. The tack property is very important for tyre applications where multiple layers must adhere to each other. The lack of adequate tack may lead to failure of the final product. Long-chain and branched alkyl phenol-based novolac resins have been recommended as tackifier. 

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