5- Ethylidene-2-norbomene

Ethene/propene/diene monomer rubbers (EPDM) are elastomeric terpoly-mers used in the production of sealants, tubing and gaskets and, in the USA, is used in roofing applications. As the name suggests they are prepared by the polymerization of mixtures of ethene, propene and diene monomers, to form cross-links. By far the most common diene used is 5-ethylidene-2-norbomene (ENB). 

Process for preparing 5-ethylidene-2-norbomene with high quality , US Patent 4727204 to Sumitomo, 1988. 

Copolymers and terpolymers of ethylene and propene, commonly known as EPM and EPDM polymers, respectively, are useful elastomers [Ver Strate, 1986], EPM and EPDM are acronyms for ethylene-propene monomers and ethylene-propene-diene monomers, respectively. The terpolymers contain up to about 4 mol% of a diene such as 5-ethylidene-2-norbomene, dicyclopentadiene, or 1,4-hexadiene. A wide range of products are available, containing 40-90 mol% ethylene. The diene, reacting through one of its double bonds, imparts a pendant double bond to the terpolymer for purposes of subsequent crosslinking (Sec. 9-2b). 

These requirements have met using a mixed catalystic system consisting of an iron catalyst complex that can oligomerize ethylene and a zirconium transition metal complex that can copolymerize ethylene and the nonconjugated monomer 5-ethylidene-2-norbomene. Using this catalytic pair nonbrancy poly(ethylene-co5-ethylidene-2-norbomene) and poly (ethylene-col,4-hexadiene) were prepared. 

A 600-ml Parr reactor was charged with 5 ml toluene and 4.2 ml of 13.5 wt% toluene solution of methylaluminoxane. This was sequentially treated with a zirconium complex (2.0 mg) dissolved in 2 ml toluene, 0.1 wt% toluene solution of iron biphenyl derivative (433 mg), 30 ml 5-ethylidene-2-norbomene, and 120 ml 2,2,4-trimethyl-pentane. The autoclave was sealed and heated to 65°C and then pressurized with ethylene to 1.24 MPa. The reaction mixture was heated to 90°C for 2 hours, cooled to ambient temperature, and vented. The mixture was slowly poured into 400 ml of methanol and then treated with 6 ml of 12 M hydrochloric. It was stirred for 25 minutes at ambient temperature, filtered, washed with methanol six times, and 3.06 g of product isolated as a white powdery solid. 

As was mentioned, cycloaddition of unactivated hydrocarbons, namely, that of cyclopentadiene, has practical significance. 5-Vinyl-2-norbomene is produced by the cycloaddition of cyclopentadiene and 1,3-butadiene546,547 [Eq. (6.96)] under conditions where side reactions (polymerization, formation of tetrahydroindene) are minimal. The product is then isomerized to 5-ethylidene-2-norbomene, which is a widely used comonomer in the manufacture of an EPDM (ethylene-propylene-diene monomer) copolymer (see Section 13.2.6). The reaction of cyclopentadiene (or dicyclopentadiene, its precursor) with ethylene leads to norbomene548,549 [Eq. (6.97)] 550... 

With larger amount of propylene a random copolymer known as ethylene-propylene-monomer (EPM) copolymer is formed, which is a useful elastomer with easy processability and improved optical properties.208,449 Copolymerization of ethylene and propylene with a nonconjugated diene [EPDM or ethylene-propylene-diene-monomer copolymer] introduces unsaturation into the polymer structure, allowing the further improvement of physical properties by crosslinking (sulfur vulcanization) 443,450 Only three dienes are employed commercially in EPDM manufacture dicyclopentadiene, 1,4-hexadiene, and the most extensively used 5-ethylidene-2-norbomene. 

AES (acrylonitrile-EPDM-styrene) is a blend of SAN and EPDM. SAN is a statistic copolymer of styrene and acrylonitrile. EPDM is an elastomeric terpo-lymer of ethylene, propylene and a nonconjugated diene. The diene studied here was 5-ethylidene-2-norbomene. The total content of EPDM was 34mole% [6]. The diene represented 8 mole% of the EPDM and the SAN phase was composed of 80 mole% of styrene and 20 mol% of acrylonitrile. The AES films were irradiated at / > 300 nm at 60 °C in the presence of oxygen. The photoproducts resulting from the photooxidation of each components of AES were identified by FTIR spectroscopy coupled with the same chemical and physical treatments as mentioned above for the previous studies. As pointed out in the literature [17], the EPDM component is more reactive than the copolymer SAN towards photooxidation. 

Since the early report by Kaminsky and Miri on the terpolymerization of ethylene, propylene, and 5-ethylidene-2-norbomene with Cp2ZrMe2 in 1985, other terpolymerization studies have appeared. Addition of a diene reduces... 

Norbornene 5-Phenyl-2-norbomene 5-Vinyl-2-norbomene 5-Ethylidene-2-norbomene... 

As a consequence of the situation depicted above, terpolymers based on ethylene and propylene are expected to contain different amounts of brandling33 or gel34, even when they contain only single olefinic unsaturation. It has been calculated34 that in the case of terpolymers based on 5-ethylidene-2-norbomene (ENB) the gel point is passed at about 0.2 wt % of ENB. 

Nonuniform vulcanization networks in miscible blends of elastomers have a strong effect on tensile strength and elongation. These networks have an intermolecular distribution in crosslink density and are composed of different concentrations of crosslinkable sites in the components of the blend. Differences in the level of the enchained diene (5-ethylidene-2-norbomene) for EPDM... 

Synonyms Bicycio (2.2.1) hept-2-ene, 5-ethylidene- ENB 5-Ethylidenebicyclo (2,2,1) hept-2-ene Ethylidene norbornene 5-Ethylidene-2-norbomene 2-Norbomene, 5-ethylidene-Empirical C9H12... 

Copolymers of ethylene (E) or propylene (P) with acrylic acid (AA) or methacrylic acid (MA) were obtained from SP2 (USA) and used as received (EAA, PAA, PEAA, PMA). Copolymers of ethylene and vinyl alcohol (EVOH) were prepared by hydrolysis (NaOH 0,5M in methanol, reflux, 48 h), of commercial ethylene-vinyl acetate copolymers (EVA, Elf-Atochem) containing 5, 9, 14, and 18 w% of acetate. Hydroperoxides of EPDM based on 5-ethylidene-2-norbomene (0.7 mol Kg" Exxon) and polyoctenamer (Vestenamer, VEST, HUls) resulted from a reaction of polymer films with singlet oxygen. 

EPM [poly(ethylene-co-propylene)] and EPDM [poly(ethylene-co-propylene-co-5-ethylidene-2-norbomene)P can be metallocene catalyst polymerized. Metallocene catalyst technologies include (1) Insite, a constrained geometry group of catalysts used to produce AfiGnity polyolefin plastomers (POP), Elite PE, Nordel EPDM, and Engage polyolefin elastomers (POP) and (2) Exxpol ionic metallocene catalyst compositions used to produce Exact plastomer octene copolymers.2 Insite technology produces EPDM-based Nordel IP with property consistency and predictability (see Sec. 3.2.2). 

The most commonly used third monomer is 5-ethylidene-2-norbomene [16219-75-3] (2), or ENB ... 

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