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Saponification In Art Conservation
Saponification is a process of converting esters into soaps and alcohols by the action of aqueous alkali (for example, aqueous sodium hydroxide solutions). Soaps are salts of fatty acids, which in turn are carboxylic acids with long carbon chains. Sodium stearate is a typical soap. Saponification of fats Vegetable oils and animal fats are the traditional materials that are saponified. These greasy materials, triesters called triglycerides, are mixtures derived from diverse fatty acids. Triglycerides can be converted to soap in either a one- or a two-step process. In the traditional one-step process, the triglyceride is treated with a strong base (e.g. lye), which cleaves the ester bond, releasing fatty acid salts (soaps) and glycerol. This process is also the main industrial method for producing glycerol. In some soap-making, the glycerol is left in the soap. If necessary, soaps may be precipitated by salting it out with sodium chloride. Fat in a corpse converts into adipocere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soap
Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are used as thickeners, components of some lubricants, and precursors to catalysts. When used for cleaning, soap solubilizes particles and grime, which can then be separated from the article being cleaned. In hand washing, as a surfactant, when lathered with a little water, soap kills microorganisms by disorganizing their membrane lipid bilayer and denaturing their proteins. It also emulsifies oils, enabling them to be carried away by running water. Soap is created by mixing fats and oils with a base. A similar process is used for making detergent which is also created by combining chemical compounds in a mixer. Humans have used soap for millennia. Evidence exists for the production of soap-like materials in ancient Babylon around 2800 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adipocere
Adipocere (), also known as corpse wax, grave wax or mortuary wax, is a wax-like organic substance formed by the anaerobic bacterial hydrolysis of fat in tissue, such as body fat in corpses. In its formation, putrefaction is replaced by a permanent firm cast of fatty tissues, internal organs, and the face. History Adipocere was first described by Sir Thomas Browne in his discourse ''Hydriotaphia, Urn Burial'' (1658): The chemical process of adipocere formation, saponification, came to be understood in the 17th century when microscopes became widely available. In 1825, physician and lecturer Augustus Granville is believed to have (somewhat unwittingly) made candles from the adipocere of a mummy and used them to light the public lecture he gave to report on the mummy's dissection. Granville apparently thought that the waxy material from which he made the candles had been used to preserve the mummy, rather than its being a product of the saponification of the mummified body. The b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myristic Acid
Myristic acid (IUPAC name: tetradecanoic acid) is a common saturated fatty acid with the molecular formula CH3(CH2)12COOH. Its salts and esters are commonly referred to as myristates or tetradecanoates. It is named after the binomial name for nutmeg (''Myristica fragrans''), from which it was first isolated in 1841 by Lyon Playfair, 1st Baron Playfair, Lyon Playfair. Occurrence Nutmeg#Nutmeg butter, Nutmeg butter has 75% trimyristin, the triglyceride of myristic acid. Besides nutmeg, myristic acid is found in palm kernel oil, coconut oil, butterfat, 8–14% of bovine milk, and 8.6% of breast milk as well as being a minor component of many other animal fats. It is found in spermaceti, the crystallized fraction of oil from the sperm whale. It is also found in the rhizomes of the Iris (plant), Iris, including Orris root. Chemical behaviour Myristic acid acts as a Lipid-anchored protein, lipid anchor in biomembranes. Reduction (chemistry), Reduction of myristic acid yields myristy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrochloric Acid
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid Acid strength is the tendency of an acid, symbolised by the chemical formula HA, to dissociate into a proton, H+, and an anion, A-. The dissociation of a strong acid in solution is effectively complete, except in its most concentrated solutions .... It is a component of the gastric acid in the digestive systems of most animal species, including humans. Hydrochloric acid is an important laboratory reagent and industrial chemical. History In the early tenth century, the Persian physician and alchemist Abu Bakr al-Razi ( 865–925, Latin: Rhazes) conducted experiments with sal ammoniac (ammonium chloride) and vitriol (hydrated sulfates of various metals), which he distilled together, thus producing the gas hydrogen chloride. In doing so, al-Razi may have stumbled upon a primitive method ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethyl Ether
Diethyl ether, or simply ether, is an organic compound in the ether class with the formula , sometimes abbreviated as (see Pseudoelement symbols). It is a colourless, highly volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It is commonly used as a solvent in laboratories and as a starting fluid for some engines. It was formerly used as a general anesthetic, until non-flammable drugs were developed, such as halothane. It has been used as a recreational drug to cause intoxication. Production Most diethyl ether is produced as a byproduct of the vapor-phase hydration of ethylene to make ethanol. This process uses solid-supported phosphoric acid catalysts and can be adjusted to make more ether if the need arises. Vapor-phase dehydration of ethanol over some alumina catalysts can give diethyl ether yields of up to 95%. Diethyl ether can be prepared both in laboratories and on an industrial scale by the acid ether synthesis. Ethanol is mixed with a stro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nutmeg
Nutmeg is the seed or ground spice of several species of the genus ''Myristica''. ''Myristica fragrans'' (fragrant nutmeg or true nutmeg) is a dark-leaved evergreen tree cultivated for two spices derived from its fruit: nutmeg, from its seed, and mace, from the seed covering. It is also a commercial source of an essential oil and nutmeg butter. Conifers of the genus ''Torreya'', commonly known as the nutmeg yews, have edible seeds of similar appearance, but are not closely related to ''Myristica fragrans'', and are not used as a spice. Indonesia is the main producer of nutmeg and mace. If consumed in amounts exceeding its typical use as a spice, nutmeg powder may produce allergic reactions, cause contact dermatitis, or have psychoactive effects. Although used in traditional medicine for treating various disorders, nutmeg has no scientifically confirmed medicinal value. Common nutmeg Nutmeg is the spice made by grinding the seed of the fragrant nutmeg tree (''Myristica fragra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimyristin
Trimyristin is a saturated fat and the triglyceride of myristic acid with the chemical formula C45H86O6. Trimyristin is a white to yellowish-gray solid that is insoluble in water, but soluble in ethanol, acetone, benzene, chloroform, dichloromethane, diethyl ether, ether, and TBME. Occurrence Trimyristin is found naturally in many vegetable fats and oils. Isolation from nutmeg The isolation of trimyristin from powdered nutmeg is a common introductory-level college organic chemistry experiment. It is an uncommonly simple natural product resource extraction, extraction because nutmeg oil generally consists of over eighty percent trimyristin. Trimyristin makes up between 20-25% of the overall mass of dried, ground nutmeg. Separation is generally carried out by steam distillation and purification uses extraction from ether followed by distillation or rotary evaporation to remove the volatile solvent. The extraction of trimyristin can also be done with diethyl ether at room temperatur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Strength
Acid strength is the tendency of an acid, symbolised by the chemical formula HA, to dissociate into a proton, H+, and an anion, A-. The dissociation of a strong acid in solution is effectively complete, except in its most concentrated solutions. :HA -> H+ + A- Examples of strong acids are hydrochloric acid (HCl), perchloric acid (HClO4), nitric acid (HNO3) and sulfuric acid (H2SO4). A weak acid is only partially dissociated, with both the undissociated acid and its dissociation products being present, in solution, in equilibrium with each other. :HA H+ + A- Acetic acid (CH3COOH) is an example of a weak acid. The strength of a weak acid is quantified by its acid dissociation constant, K_\ce value. The strength of a weak organic acid may depend on substituent effects. The strength of an inorganic acid is dependent on the oxidation state for the atom to which the proton may be attached. Acid strength is solvent-dependent. For example, hydrogen chloride is a strong acid in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthoester
In organic chemistry, an ortho ester is a functional group containing three alkoxy groups attached to one carbon atom, i.e. with the general formula . Orthoesters may be considered as products of exhaustive alkylation of unstable orthocarboxylic acids and it is from these that the name 'ortho ester' is derived. An example is ethyl orthoacetate, , more correctly known as 1,1,1-triethoxyethane. Synthesis Ortho esters can be prepared by the Pinner reaction, in which nitriles react with alcohols in the presence of one equivalent of hydrogen chloride. The reaction proceeds by formation of imido ester hydrochloride: :RCN + R′OH + HCl → C(OR′)=NH2sup>+Cl− Upon standing in the presence of excess alcohol, this intermediate converts to the ortho ester: : C(OR′)=NH2sup>+Cl− + 2R′OH → RC(OR′)3 + NH4Cl The reaction requires anhydrous conditions. Although a less common method, ortho esters were first produced by reaction of 1,1,1-trichloroalkanes with sodium alkoxide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
