This article may be too technical for most readers to understand.(June 2021) |
Narrow-range ethoxylates (NREs) in chemistry are fatty alcohol polyglycol ethers with a narrow homolog distribution and are known nonionic surfactants. They can be produced industrially, for example, by the addition of ethylene oxide onto fatty alcohols in the presence of suitable catalysts (layer compounds which have been calcined or hydrophobized with fatty acids). [a] This process can also be carried out on a variety of other hydrophobes and using different alkoxylating compounds (e.g., propylene oxide and butylene oxide) by modifying the catalyst properties.
An ethoxylation reaction proceeds under an inert atmosphere with an amount of heat depending on the starting material. The reaction proceeds via the epoxide (in this case ethylene oxide) ring opening and activation of the nucleophile, ring, or combination thereof via the catalyst.
With conventional catalysts (i.e. potassium hydroxide, sodium hydroxide, etc.) one obtains a distribution of ethoxymers. If one targets a 12 mole ethoxylate with a conventional alkaline earth hydroxide, one could expect to get a broad range of ethoxylates with n being anywhere from 3 to 30 moles of EO. With narrow-range catalysts a much tighter distribution can be obtained.
Narrow-range surfactants like alcohol ethoxylates and propoxylates can be incorporated into alkyl ether sulfates or mixed with other anionic surfactants and exhibit beneficial properties such as reduced irritation to skin/eyes and lower free alcohol content.
In chemistry, an alcohol, is a type of organic compound that carries at least one hydroxyl functional group bound to a saturated carbon atom. Alcohols range from the simple, like methanol and ethanol, to complex, like sugars and cholesterol. The presence of an OH group strongly modifies the properties of hydrocarbons, conferring hydrophilic (water-loving) properties. The OH group provides a site at which many reactions can occur.
In organic chemistry, ethers are a class of compounds that contain an ether group—a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group. They have the general formula R−O−R′, where R and R′ represent the organyl groups. Ethers can again be classified into two varieties: if the organyl groups are the same on both sides of the oxygen atom, then it is a simple or symmetrical ether, whereas if they are different, the ethers are called mixed or unsymmetrical ethers. A typical example of the first group is the solvent and anaesthetic diethyl ether, commonly referred to simply as "ether". Ethers are common in organic chemistry and even more prevalent in biochemistry, as they are common linkages in carbohydrates and lignin.
In chemistry, an ester is a compound derived from an acid in which the hydrogen atom (H) of at least one acidic hydroxyl group of that acid is replaced by an organyl group. These compounds contain a distinctive functional group. Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well. According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well, but not according to the IUPAC.
Petrochemicals are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as maize, palm fruit or sugar cane.
Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. The word "surfactant" is a blend of surface-active agent, coined in 1950. As they consist of a water-repellent and a water-attracting part, they enable water and oil to mix; they can form foam and facilitate the detachment of dirt.
Transesterification is the process of exchanging the organic functional group R″ of an ester with the organic group R' of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. Strong acids catalyze the reaction by donating a proton to the carbonyl group, thus making it a more potent electrophile. Bases catalyze the reaction by removing a proton from the alcohol, thus making it more nucleophilic. The reaction can also be accomplished with the help of enzymes, particularly lipases.
Ethylene oxide is an organic compound with the formula C2H4O. It is a cyclic ether and the simplest epoxide: a three-membered ring consisting of one oxygen atom and two carbon atoms. Ethylene oxide is a colorless and flammable gas with a faintly sweet odor. Because it is a strained ring, ethylene oxide easily participates in a number of addition reactions that result in ring-opening. Ethylene oxide is isomeric with acetaldehyde and with vinyl alcohol. Ethylene oxide is industrially produced by oxidation of ethylene in the presence of a silver catalyst.
In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ethers. They are produced on a large scale for many applications. In general, low molecular weight epoxides are colourless and nonpolar, and often volatile.
Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene. Alkylating agents are reagents for effecting alkylation. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a premium blending stock for gasoline. In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the class of drugs called alkylating antineoplastic agents.
In organic chemistry, ethoxylation is a chemical reaction in which ethylene oxide adds to a substrate. It is the most widely practiced alkoxylation, which involves the addition of epoxides to substrates.
Fatty alcohols (or long-chain alcohols) are usually high-molecular-weight, straight-chain primary alcohols, but can also range from as few as 4–6 carbons to as many as 22–26, derived from natural fats and oils. The precise chain length varies with the source. Some commercially important fatty alcohols are lauryl, stearyl, and oleyl alcohols. They are colourless oily liquids (for smaller carbon numbers) or waxy solids, although impure samples may appear yellow. Fatty alcohols usually have an even number of carbon atoms and a single alcohol group (–OH) attached to the terminal carbon. Some are unsaturated and some are branched. They are widely used in industry. As with fatty acids, they are often referred to generically by the number of carbon atoms in the molecule, such as "a C12 alcohol", that is an alcohol having 12 carbons, for example dodecanol.
In organic chemistry a halohydrin is a functional group in which a halogen and a hydroxyl are bonded to adjacent carbon atoms, which otherwise bear only hydrogen or hydrocarbyl groups. The term only applies to saturated motifs, as such compounds like 2-chlorophenol would not normally be considered halohydrins. Megatons of some chlorohydrins, e.g. propylene chlorohydrin, are produced annually as precursors to polymers.
Straight-chain terminal alkenes, also called linear alpha olefins (LAO) or normal alpha olefins (NAO), are alkenes (olefins) having a chemical formula CnH2n, distinguished from other alkenes with a similar molecular formula by being terminal alkenes, in which the double bond occurs at the alpha position, and by having a linear (unbranched) hydrocarbon chain.
Sodium myreth sulfate is a mixture of organic compounds with both detergent and surfactant properties. It is found in many personal care products such as soaps, shampoos, and toothpaste. It is an inexpensive and effective foaming agent. Typical of many detergents, sodium myreth sulfate consists of several closely related compounds. Sometimes the number of ethylene glycol ether units (n) is specified in the name as myreth-n sulfate, for example myreth-2 sulfate.
Kolliphor EL, formerly known as Cremophor EL, is the registered trademark of BASF Corp. for its version of polyethoxylated castor oil. It is prepared by reacting 35 moles of ethylene oxide with each mole of castor oil. The resulting product is a mixture : the major component is the material in which the hydroxyl groups of the castor oil triglyceride have been ethoxylated with ethylene oxide to form polyethylene glycol ethers. Minor components are the polyethyelene glycol esters of ricinoleic acid, polyethylene glycols and polyethylene glycol ethers of glycerol. Kolliphor EL is a synthetic, nonionic surfactant used to stabilize emulsions of nonpolar materials in water.
In organosulfur chemistry, organosulfates are a class of organic compounds sharing a common functional group with the structure R−O−SO−3. The SO4 core is a sulfate group and the R group is any organic residue. All organosulfates are formally esters derived from alcohols and sulfuric acid although many are not prepared in this way. Many sulfate esters are used in detergents, and some are useful reagents. Alkyl sulfates consist of a hydrophobic hydrocarbon chain, a polar sulfate group and either a cation or amine to neutralize the sulfate group. Examples include: sodium lauryl sulfate and related potassium and ammonium salts.
Cleaning agents or hard-surface cleaners are substances used to remove dirt, including dust, stains, foul odors, and clutter on surfaces. Purposes of cleaning agents include health, beauty, removing offensive odors, and avoiding the spread of dirt and contaminants to oneself and others. Some cleaning agents can kill bacteria and clean at the same time. Others, called degreasers, contain organic solvents to help dissolve oils and fats.
In organic chemistry, the Ziegler process is a method for producing fatty alcohols from ethylene using an organoaluminium compound. The reaction produces linear primary alcohols with an even numbered carbon chain. The process uses an aluminum compound to oligomerize ethylene and allow the resulting alkyl group to be oxygenated. The usually targeted products are fatty alcohols, which are otherwise derived from natural fats and oils. Fatty alcohols are used in food and chemical processing. They are useful due to their amphipathic nature. The synthesis route is named after Karl Ziegler, who described the process in 1955.
C12-15 pareth-12 (INCI name) is an emulsifier and surfactant commonly used in cosmetics formulations. It is a polyethylene glycol ether formed by combining synthetic C12–C15 fatty alcohols with 12 moles of ethylene oxide.
In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as RO−, where R is the organyl substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands. Alkoxides, although generally not stable in protic solvents such as water, occur widely as intermediates in various reactions, including the Williamson ether synthesis. Transition metal alkoxides are widely used for coatings and as catalysts.