5- ethylidene-2-norbornene

Toxicology. By analogy to effects caused by other acrylates, 2-ethylhexyl acrylate (EHA) is expected to be an irritant of the eyes, nose, and skin. 

Dermal sensitization to EHA has been documented from exposure to its presence in adhesive tape. This potential has been confirmed in the guinea pig.  

In a lifetime dermal oncogenesis study in mice, 20 mg EHA in acetone was applied 3 times weekly for their lifespan. There were 40 mice in the group at the start of the study. Two animals developed squamous cell carcinomas, and four other animals had squamous cell papillomas. The first tumor was observed after 11 months of treatment. None of the acetone-treated controls developed tumors. There was an apparent increase in the frequency of chronic nephritis in the EHA-treated mice (68% compared with 15% in controls). Treatment with EHA may have exacerbated the onset and development of this condition, which is normally seen in aged mice. 

In another smdy, skin tumors, including papillomas, squamous cell carcinomas, and malignant melanomas, were seen in mice receiving skin applications of 21% or 86.5% EHA in 2 5 pi of acetone three times per week for 2 years.  

No skin tumors were observed in another strain of mice receiving up to 85% EHA in acetone for up to 2 years. Hyperkeratosis and hyperplasia occurred in all treated groups.  

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The violent polymerisation of acryl acid caused a violent fire on a boat that was transporting it. The investigation showed that this acid contained ethylidene norbornene, which is a very oxidisable compound that forms a peroxide in air, which caused the acid polymerisation. 

Ethylidene norbornene, from butadiene, 4 383, 384 Ethyl iodide, 14 376... 

Toxieology. Ethylidene norbornene is an irritant of the eyes and mucous membranes and at high concentrations causes central nervous system effects in animals. 

Ethylidene norbornene was not mutagenic or clastogenic in a variety of in vitro assays. The 2003 ACGIH ceiling-threshold limit value (C-TLV) for ethylidene norbornene is 5 ppm (25 mg/m"). 

Kinkead ER, Pozzani UC, Geary DL, Carpenter CP The mammalian toxicity of ethylidene norbornene. Toxicol Appl Pharmacol 20 250-259, 1971... 

Ethylene and propylene are produced primarily by the cracking of naphtha. They also are available from the fractionation of natural gas. Ethylidene norbornene is produced by reacting butadiene with cyclopentadiene. 1,4 Hexadiene is produced from butadiene and ethylene. Dicyclopentadiene is obtained as a by-product from the cracking of heavy feedstocks to produce ethylene. 

An oligomer containing pendent ethylidene norbornene was also reacted with diethyl ketomalonate as illustrated in Eq. 1 and discussed by the author. 

ETHYLIDENELACTIC ACID see LAGOOO ETHYLIDENE NORBORNENE see EL0500 5-ETHYLIDENE-2-NORBORNENE see EL0500 ETHYLIDICHLORARSINE see DFH200 ETHYLIDICHLOROARSINE (DOTJ see DFH200... 

C9H12 ethylidene norbornene 16219-75-3 gas 0.205 2 19875 C10H14 1 -methyl-4-propylbenzene 1074-55-1 gas 0.000 2... 

Data on a number of copolymers prepared with various catalysts are given in Table 19A [287]. An assumption in this work was that the small proportion of termonomer (ethylidene norbornene) did not interfere with E/ copolymerization. 

The addition copolymerization of norbornene-type monomers with a-olefins [21] forms the basis of EPDM (ethylene propylene diene monomer) technology. Incorporation of smaU amounts of DCPD or ethylidene norbornene (ENB) in olefinic vinyl addition polymers provides latent crosslink sites in EPDM elastomers. It is weU known in the hterature that incorporation of higher amounts of rigid, bulky multicychc olefins results in materials with higher TgS [22]. In fact, more recent work has concentrated on increasing the Tg of norbornene-type monomer/a-olefin copolymers [23]. The use of late transition metal catalysts to prepare such copolymers is reviewed in Section 4.3. 

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