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Sodium 2-anthraquinonesulfonate
Sodium 2-anthraquinonesulfonate (AMS) is a water-soluble anthraquinone derivative. In the laboratory it could be prepared by sulfonation of anthraquinone. Digester additive in papermaking AMS is used as a catalyst in production of alkaline pulping in the soda process. It goes through a redox cycle similar to that of anthraquinone Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxoan ... to give a catalytic effect. AMS was discovered as an efficient pulping catalyst before anthraquinone, but has a higher cost. References {{reflist Anthraquinones Sulfonates Organic sodium salts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthraquinone
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein the keto groups are located on the central ring. It is a building block of many dyes and is used in bleaching pulp for papermaking. It is a yellow, highly crystalline solid, poorly soluble in water but soluble in hot organic solvents. It is almost completely insoluble in ethanol near room temperature but 2.25 g will dissolve in 100 g of boiling ethanol. It is found in nature as the rare mineral hoelite. Synthesis There are several current industrial methods to produce 9,10-anthraquinone: # The oxidation of anthracene. Chromium(VI) is the typical oxidant. # The Friedel-Crafts reaction of benzene and phthalic anhydride in presence of AlCl3. o-Benzoylbenzoic acid is an intermediate. This reaction is useful for produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soda Process
Soda pulping is a chemical process for making wood pulp with sodium hydroxide as the cooking chemical. In the ''Soda-AQ'' process, anthraquinone (AQ) may be used as a pulping additive to decrease the carbohydrate degradation. The soda process gives pulp with lower tear strength than other chemical pulping processes ( sulfite process and kraft process), but has still limited use for easily-pulped materials like straw and some hardwoods. History A precursor to the soda pulping process was the paper making process developed by Matthias Koops in 1801 which involved washing wood shavings in limewater, adding soda crystals and then boiling the mixture. Soda pulping was one of the first chemical pulping methods and was invented in 1851 by Burgess (United States) and Watts (England). In France in 1852 Coupier and Mellier patented a soda process based on a 1851 invention the patent of which preceded that of Watt and Burgess, which was filed in 1854. The first mill was started in 1866 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthraquinones
''For the parent molecule 9,10-anthraquinone, see anthraquinone'' Anthraquinones (also known as anthraquinonoids) are a class of naturally occurring phenolic compounds based on the 9,10-anthraquinone skeleton. They are widely used industrially and occur naturally. Occurrence in plants : Natural pigments that are derivatives of anthraquinone are found, inter alia, in aloe latex, senna, rhubarb, and cascara buckthorn, fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ..., lichens, and some insects. A type II polyketide synthase is responsible for anthraquinone biosynthesis in the bacterium ''Photorhabdus luminescens''. Chorismate, formed by isochorismate synthase in the shikimate pathway, is a precursor of anthraquinones in ''Morinda citrifolia''. Tests for anthraquinones in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfonates
In organosulfur chemistry, a sulfonate is a salt or ester of a sulfonic acid. It contains the functional group , where R is an organic group. Sulfonates are the conjugate bases of sulfonic acids. Sulfonates are generally stable in water, non-oxidizing, and colorless. Many useful compounds and even some biochemicals feature sulfonates. Sulfonate salts Anions with the general formula are called sulfonates. They are the conjugate bases of sulfonic acids with formula . As sulfonic acids tend to be strong acids, the corresponding sulfonates are weak bases. Due to the stability of sulfonate anions, the cations of sulfonate salts such as scandium triflate have application as Lewis acids. A classic preparation of sulfonates is the Strecker sulfite alkylation, in which an alkali sulfite salt displaces a halide, typically in the presence of an iodine catalyst: :RX + M2SO3 -> RSO3M + MX An alternative is the condensation of a sulfonyl halide with an alcohol in pyridine: :ROH + R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
