Ethylene-propylene-elastomer

Includes acrylic acid, aHyl chloride, ethylene—propylene elastomers, and miscellaneous uses. 

Ethylene—propylene elastomers exhibit a high resistance to oxygen, ozone, and heat, and are used in motor parts because of thek excellent low... 

Bases like water or ammonia [33] have been found to enhance cross-linking in polymers like PP and ethylene-propylene elastomers. The mechanism of action of various indirect cross-link promoters is reported in the literature [77-81]. 

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]. 

Olefin metathesis technology, in polymer synthesis, 26 944-948 Olefin oligomerization, 16 111 Olefin oxides, alkanolamines from (with ammonia), 2 122-140 Olefin polymerization, organic titanium compounds in, 25 122 Olefin(ic) polymers, 17 699-709 ethylene-propylene elastomers, 17 705-707... 

Table II gives our description for each occurring methylene sequence in terms of conditional probabilities. We take a measured nmr spectrum of an ethylene propylene elastomer and derive a set of six reaction probabilities that fit it best. For possible sets of probability values, a spectrum is calculated and a sum of weighted squares of errors is found. The set of probability values having the smallest sum of weighted squares of error is used as a starting point to minimize the error using the...

Terpolymerization, the simultaneous polymerization of three monomers, has become increasingly important from the commercial viewpoint. The improvements that are obtained by copolymerizing styrene with acrylonitrile or butadiene have been mentioned previously. The radical terpolymerization of styrene with acrylonitrile and butadiene increases even further the degree of variation in properties that can be built into the final product. Many other commercial uses of terpolymerization exist. In most of these the terpolymer has two of the monomers present in major amounts to obtain the gross properties desired, with the third monomer in a minor amount for modification of a special property. Thus the ethylene-propylene elastomers are terpolymerized with minor amounts of a diene in order to allow the product to be subsquently crosslinked. 

Apart from binary polymer blends, also blends consisting of three different polymers have foimd technical applications. Belonging to this group are mixtures of polypropylene, polyethylene, and ethylene/propylene elastomers. 

Vulcanising Ethylene—Propylene Elastomers, Technical Bulletin, No. ORC-104C, Hercules, Inc., Wilmington, Del. 

Ver Strate, G., Ethylene-Propylene Elastomers , in Encyclopedia of Polymer Science and Engineering, Wiley-Interscience, John Wiley Sons, New York, 1986, Vol. 6, pp. 523-564. 

These post-polymerization reactions are very expensive so HNBRs usually command a premium price. HNBR is usually cured with peroxides, similar to ethylene-propylene elastomers, because it has no unsaturation for a conventional sulfur cure system. 

Hexadiene is utilized as a third co-monomer in ethylene/propylene elastomers. While the terminal double bond is incorporated into the polymeric chain, the internal one is not and can be cross-linked (vulcanized) to confer... 

Impact-modified polypropylenes are produced by combining the homopolymer with an ethylene-propylene copolymer rubber. Ziegler-Natta processes yield such products in cascaded reactors. The first reactor in the sequence produces a rigid polymer with a high propylene content and feeds the second reactor, where the ethylene-propylene elastomer is polymerized in intimate mixture with the first material. 

The zinc oxide, titanium dioxide and cadmium sulphide photo-catalysed oxidation of an ethylene-propylene elastomer has been... 

The phase diagram (see Figure 1) shows that there are two solution processes a low-temperature process (below 100 °C) for the production of amorphous copolymers like ethylene/propylene elastomers (EPR or EPM) [2], and a high-tempera-ture process (far beyond 100 °C) for the production of semicrystalline homo- and copolymers like high-density polyethylenes (PE-HD), linear low-density poly-ethylenes (PE-LLD) and ethylene waxes [1, 3]. Polypropylenes (PP) cannot be made in high-temperature solution processes, except for propylene waxes. 

With the high-temperature solution polymerization processes, various ethylene homo- and copolymers with different average molecular mass and copolymer compositions are produced. The product portfolio comprises PE-HD, PE-LLD, PE-VLD, and the ethylene/propylene elastomers (EPM, EPDM) (see Figure 2). The thermoplastic products have a wide range of applications [1]. The elastomeric ethylene/propylene copolymers can also be applied widely in the automotive industry, for plastics modification, in industrial applications such as seals, in electrical cables, and in tires [2], Uncured ethylene/propylene copolymers are applicable as viscosity index improvers for lubricant oils [5]. 

BPIC [PPG]. TM for technical grade of ter-butylperoxyisopropyl carbonate, a polymerization initiator for acrylic, ethylene, styrene, and other monomers, and a cross-linking agent for silicone and ethylene propylene elastomers. 

EniChem s expertise lies in petrochemicals, and over half of its production is of ethylene, propylene, elastomers and polystyrene. 

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