Ethylene Oxide

Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.
Related to Ethylene Oxide: ethyl acetate, ethylene oxide sterilization

ethylene oxide

[′eth·ə‚lēn ′äk‚sīd]
(organic chemistry)
(CH2)2O A colorless gas, soluble in organic solvents and miscible in water, boiling point 11°C; used in organic synthesis, for sterilizing, and for fumigating. Also known as 1,2-epoxyethane.

Ethylene Oxide


(also epoxyethane or oxiran), the simplest epoxide.

A cyclic ether with an a-epoxide three-membered ring, ethylene oxide has the structural formula

It takes the form of a colorless gas with an ethereal odor, and it has a melting point of – 111.3°C, a boiling point of 10.7°C, and a density of 0.891 g/cm3 at 4°C. Ethylene oxide is readily soluble in water and such organic solvents as ethanol and ether. Highly flammable, it forms explosive mixtures with air when found in concentrations of 3 to 80 percent by volume.

The chemical properties of ethylene oxide are determined by the epoxide ring, which is strained and therefore relatively easy to open by the action of high temperatures or various chemical reagents. Thus, upon heating to 400°C (or 150°-300°C in the presence of Al2O3), ethylene oxide isomerizes into acetaldehyde. The hydrogenation of ethylene oxide over nickel at 80°C yields ethyl alcohol according to the reaction

Hydrohalogenation produces the corresponding ethylene halohydrin, as shown in the equation

In these and many analogous reactions, ethylene oxide acts as an alkylating agent for the introduction of the β-hydroxyethyl group, HOCH2CH2—. Because of this property, it is commonly used in industry and laboratory practice for the production of such valuable chemicals as ethylene cyanohydrin (by reaction with hydrocyanic acid); ethylene glycol and its monoethers, which are known as cellosolves (by hydration and alcoholysis); ethanolamines (by reaction with ammonia); β-mercaptoethanol (HSCH2CH2OH; by reaction with hydrogen sulfide); and β-phenylethyl alcohol (by the Friedel-Crafts reaction with benzene).

Polymerization, which also proceeds by means of the cleavage of a C—O bond, is also characteristic of ethylene oxide. Thus, passage of ethylene oxide vapor over NaHSO4 at 110°–160°C yields the dimer dioxane. Ethylene oxide is readily polymerized—sometimes explosively—at ordinary temperatures by the catalytic action of tertiary amines or stannic chloride. Polyethylene oxides, [—CH2—CH2—O—]n, have molecular weights ranging from 102 to 107. A distinction is made between the polymers of low molecular weight (polyethylene glycols, which have a molecular weight of up to 40,000) and the polymers of high molecular weight (with a weight of 0.5–10 million). Those of low molecular weight are liquids or waxy products and are obtained by the catalytic polymerization of ethylene oxide at 100°–150°C. They are used in the textile industry as wetting agents, softeners, and anticlinging agents; they are also used in cosmetics and as detergent components. The polymers of high molecular weight are produced in industry by catalytic suspension polymerization at 20°–50°C. These polymers are solids with good thermoplastic and mechanical properties and some solubility in water. They are used as thickening agents in the textile industry and as flocculating agents (to reduce hydrodynamic resistance to water flow).

Upon condensation with higher alcohols (including oleyl, lauryl, and stearyl alcohol), alkylphenols (such as isooctylphenol), and fatty carboxylic acids, ethylene oxide yields polyethylene glycol ethers of the type RO(CH2CH2O)n—H, where R is an organic radical and n is an integer with a value between 6 and 30, inclusive. These ethers are used as emulsifiers and detergent components. Crown ethers (cyclic ethers that are obtained from ethylene oxide) are commonly used in organic synthesis for separating the ion pairs of various salts in aprotic bipolar solvents; crown 18–6, for example, is used for complexing the potassium ion.

The principal industrial methods for the production of ethylene oxide are the dehydrochlorination of ethylene chlorohydrin and the catalytic oxidation of ethylene by atmospheric oxygen at 200°–300°C over a catalyst containing metallic silver. Ethylene oxide is an important reagent in fine organic synthesis; for example, the reaction of ethylene oxide with acetoacetic ester yields acetobutyrolactone, which is used in the production of vitamin B, and is an intermediate in the preparation of antimalarial agents.

Ethylene oxide is toxic. In small doses, it has a narcotic effect, and in large quantities it irritates the mucous membranes and causes asphyxiation and emphysema. The maximum permissible concentration of ethylene oxide in the air is 0.001 mg per liter.

References in periodicals archive ?
1 Polyols application in ethylene oxide market, estimates and forecast, 2011 - 2018 (kilo tons), (USD Million)
Table 5: Global Ethylene Oxide Capacity by Geographic
Table 24: World Recent Past, Current & Future Analysis forConsumption of Ethylene Oxide in Other Applications byGeographic Region - North America, Japan, Europe,Asia-Pacific, Middle East and Latin American MarketsIndependently Analyzed with Annual Consumption Figures inThousand Tons for Years 2009 through 2017 (includescorresponding Graph/Chart) II-43
Revenuesfor Steam/Autoclave, Ethylene Oxide, Gas Plasma,
Petrochemical Industry: Global Ethylene Oxide (EO) Industry
Thus, the major thrust of this study was to ascertain the effects of real-time aging, after ethylene oxide and gamma radiation sterilization, on the physical pr a wide variety of thermoplastic materials.
In addition to the analytical part, the report provides a range of tables and figures which all together give a true insight into the national, regional and global markets for ethylene oxide.
Applications include HDPE, LLDPE, LDPE, ethylene oxide, EDC, ethylbenzene and acetaldehyde, ethanol, linear alcohols, vinyl acetate, and alpha-olefins.
Epichlorohydrin homopolymer contains 38% chlorine by weight, while the 1:1 copolymer of epichlorohydrin and ethylene oxide contains 26%.
The materials can be sterilized with ethylene oxide and gamma or e-beam radiation.
The 2,400 acre oxides and olefin plant in Port Neches produces ethylene, ethylene oxide, ethylene glycols, propylene, propylene oxide, propylene glycols, nonylphenol, diglycolamine, ethanolamines, morpholine and surfactants for intermediate and end-use products such as antifreeze, detergents, shampoos, soaps, textiles and waxes.

Full browser ?