Ethylene propylene diene monomer rubber

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

Process systems handling polymers and resins (e.g., butyl rubber or ethylene-propylene diene monomer rubbers) are often subject to plugging at dead-end locations such as PR valve inlets. In extreme cases, complete blockage of inlet piping and valve nozzle can result. This problem can be eliminated by the application of a flush-seated PR valve, in which dead-end areas are eliminated by placing the valve disc flush with the vessel wall, in the flow pattern of the contents. 

TPEs from blends of rubber and plastics constitute an important category of TPEs. These can be prepared either by the melt mixing of plastics and rubbers in an internal mixer or by solvent casting from a suitable solvent. The commonly used plastics and rubbers include polypropylene (PP), polyethylene (PE), polystyrene (PS), nylon, ethylene propylene diene monomer rubber (EPDM), natural rubber (NR), butyl rubber, nitrile rubber, etc. TPEs from blends of rubbers and plastics have certain typical advantages over the other TPEs. In this case, the required properties can easily be achieved by the proper selection of rubbers and plastics and by the proper change in their ratios. The overall performance of the resultant TPEs can be improved by changing the phase structure and crystallinity of plastics and also by the proper incorporation of suitable fillers, crosslinkers, and interfacial agents. 

Ethylene-propylene-diene monomer rubber EPDM... 

Figure 3 Examination of the acetone extract from an EPDM (ethylene propylene diene monomer) rubber using two-dimensional gas chromatography. (See Color Plate Section at the end of this book.)... 

Zinc salt of maleated ethylene-propylene diene monomer rubber... 

Butadiene could also be trimerized to give cyclododecatriene. The trimer is again used by Hulls to manufacture nylon 12 and Vestamid . The codimerization of butadiene and ethylene is used by DuPont to manufacture 1,4-hexadiene, one of the monomers of EPDM (ethylene, propylene, diene, monomers) rubber. The role of the diene monomer in EPDM rubber is to provide with two double bonds of different reactivities. The more reactive, terminal double bond takes part in the polymerization with ethylene and propylene. The less reactive internal one is used later on for cross-linking. These important catalytic reactions are shown in Fig. 7.6. 

Acrylonitrile-Ethylene/Propylene-Styrene Copolymer AES is a terpolymer obtained by grafting styrene-acrylonitrile copolymer to ethylene-propylene or ethylene-propylene-diene monomer rubber. Similar to ABS except with improved weathering resistance. 

A blend of low-density polyethylene (LDPE) polyethylene (LDPE) with the terpolymer ethylene-propylene-diene monomer rubber (EPDM) exhibits a synergistic effect on tensile strength if EPDM is partially crystalline, but a nonsynergistic effect if the EPDM is amorphous [65]. This example shows the dramatic effect that morphology can have on properties of polymer blends. The synergism apparently arises from a tendency for crystallites in the LDPE to nucleate crystalli2ation of ethylene segments in the EPDM. 

The accelerated-sulfur vulcanization of these rubbers along with the vulcanization of other rubbers, which are vulcanized by closely related technology, comprises more than 90% of all vulcanization. These rubbers include ethylene-propylene-diene-monomer rubber (EPDM), butyl rubber (HR), halobutyl rubbers, and nitrile rubber (NBR). Nevertheless, we give some consideration to vulcanization by the action of other vulcanization agents such as organic peroxides, phenolic curatives, and quinoid curatives. 

Over the years, much of the research on accelerated-sulfur vulcanization was done by using natural rubber as a model substrate. Natural rubber was the first elastomer and therefore the search for the understanding of vulcanization originated with work on natural rubber. Most of the work cited in the previous sections is related to natural rubber. However, some rather early studies have been directed to the vulcanization of butadiene 1,4-polymers (Skinner and Watson, 1969 Wolfe et al, 1329 Gregg and Katrenick, 1970). More recent is the work of Pellicioli and coworkers. Early basic work on the vulcanization of ethylene-propylene-diene-monomer rubber (EPDM) has been carried out (van den Berg et al., 1984a,b). Recently, Kuno and coworkers did basic work on EPDM networks. They found that, essentially, the vulcanizate properties depend only on the crosslink density, not on the type of curing system (Dijkhuis et al., 2009). 

As mentioned extensively, PPE is not mainly used as such, but in polymeric blends and copolymers to faciUtate the fabrication. Some of these copolymers act also as impact modifiers for example, block copolymers built from styrene, ethylene, butylene, and propylene. Naturally, the impact can be improved by using high impact poly(styrene) (HIPS) instead of ordinary PS in blends. Other impact modifiers include rubbery materials, such as poly(octenylene), and ethylene propylene diene monomer rubber. 

A process has been developed for electroplating a PPA resin, modified with ethylene propylene diene monomer rubber, ethylene-propylene rubber, and styrene-butadiene rubber. As etching solution, chromic acid is used. However, it has been found that the concentration of Cr + is crucial for the success of the method. The concentration of Cr + is in the range of 50-55 gU Low levels of Cr + result in poor adhesion of the final metal plating, while high levels of Cr + can cause the formation of small blisters in the metal plating. The influence of the process parameters on the peel strength is shown in Table 12.9. 

Dubey et compared the efficiency of different additives to promote the cross-linking of a nonmiscible ethylene propylene diene monomer rubber (EPDM)/styrene-ethlene/butylene-styrene copolymer (SEES) blend y-irradiated between 50 and 500 kGy ethyleneglycol dimethacrylate styrene-ethylene/ butylene-styrene copolymer (EGDMA), tri(propylene glycol) diacrylate (TRPGDA), trimethylol propane triacrylate (TMPTA), and trimethylol propane... 

Several elastomers including Neoprene, polyurethane, silicone and ethylene-propylene-diene monomer rubber were tested according to the UL 94 VO procedure. Each material was exposed to flame for two, one second intervals. To pass the test, each individual specimen had to cease burning 10 seconds after flame application. Of these, only a cellular silicone called Bisco passed while another manufacturer s silicone severely charred and supported a flame. 

Accelerated-sulfur vulcanization is the most widely used method. For many applications, it is the only rapid crossUnking technique that can, in a practical manner, give the delayed action required for processing, shaping, and forming before the formation of the intractable vulcanized network. It is used to vulcanize natural rubber (NR), synthetic isoprene rubber (IR), styrene-butadiene rubber (SBR), nitrile rubber (NBR), butyl rubber (HR), chlorobutyl rubber (ClIR), bromobutyl rubber (BUR), and ethylene-propylene-diene-monomer rubber (EPDM). The reactive moiety for all of these elastomers can be represented by... 

Most of the work cited in the previous sections is related to natural rubber. However, some studies have been directed to the vulcanization of butadiene 1,4-polymers [51,61,62]. Other basic work on the vulcanization of ethylene-propylene-diene-monomer rubber (EPDM) has been carried out [63,64]. 

TPO materials are defined as compounds (mixtures) of various polyolefin polymers, semicrystalline thermoplastics, and amorphous elastomers. Most TPOs are composed of polypropylene and a copolymer of ethylene and propylene called ethylene—propylene rubber (EPR) [2]. A common rubber of this type is called ethylene propylene diene monomer rubber (EPDM), which has a small amount of a third monomer, a diene (two carbon-carbon double bonds in it). The diene monomer leaves a small amount of unsaturation in the polymer chain that can be used for sulfur cross-linking. Like most TPEs, TPO products are composed of hard and soft segments. TPO compounds include fillers, reinforcements, lubricants, heat stabilizers, antioxidants, UV stabilizers, colorants, and processing aids. They are characterized by high impact strength, low density, and good chemical resistance they are used when durability and reliability are primary concerns. 

Parylene is used as a coating on electronics ranging from advanced military and aerospace electronics to general-purpose industrial products, medical devices ranging from silicone tubes to advanced coronary stents, synthetic rubber products ranging from medical grade silicone rubber to ethylene propylene diene monomer rubber (EPDM). 

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. 

The natural rubber does not generally exhibit all the desired properties for use in the rubber industry. Thus, it is possible to obtain better mechanical and physical properties at a lower cost by blending natural rubber with synthetic rubbers. Normally, natural rubber is deteriorated by ozone and thermal attacks due to its highly unsaturated backbone, and it also shows low oil and chemical resistances due to its non-polarity. However, these properties can be achieved by blending it with low unsaturated ethylene propylene diene monomer rubber, styrene butadiene rubber, carboxylate styrene butadiene rubber, nitrile butadiene rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, and acrylonitrile butadiene rubber. 

Rubber can be divided into natural rubber and synthetic rubber on the basis of its source. Natural rubber is prepared from rubber-containing plants in nature, such as a high-elasticity material produced from natural rubber trees. Synthetic rubber is a synthetic macromolecular elastic material prepared by artificial methods. The main varieties of synthetic rubber are styrene-butadiene rubber, butadiene rubber, chlo-roprene rubber, isoprene rubber, butyl rubber, and ethylene-propylene-diene monomer rubber. 

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