| 词条 | Sodium hexametaphosphate |
| 释义 |
| Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 447673815 | Reference = [1] | ImageFile = sodium hexametaphosphate.png | ImageFile_Ref = {{chemboximage|correct|??}} | ImageName = Skeletal formula of sodium hexametaphosphate | OtherNames = Calgon S Glassy sodium Graham's salt Hexasodium metaphosphate Metaphosphoric acid, hexasodium salt |Section1={{Chembox Identifiers | CASNo_Ref = {{cascite|changed|CAS}} | PubChem = 24968 | ChemSpiderID = 23340 | ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}} | EINECS = 233-343-1 | MeSHName = sodium+polymetaphosphate | SMILES = [Na]OP1(=O)OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])O1 | StdInChI = 1S/6Na.H6O18P6/c;;;;;;1-19(2)13-20(3,4)15-22(7,8)17-24(11,12)18-23(9,10)16-21(5,6)14-19/h;;;;;;(H,1,2)(H,3,4)(H,5,6)(H,7,8)(H,9,10)(H,11,12)/q6*+1;/p-6 | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = GCLGEJMYGQKIIW-UHFFFAOYSA-H | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} }} |Section2={{Chembox Properties | Formula = {{Chem|Na|6|P|6|O|18}} | MolarMass = 611.7704 g mol−1 | Appearance = White crystals | Odor = odorless | Density = 2.484 g/cm3 | MeltingPtC = 628 | BoilingPtC = 1500 | Solubility = soluble | SolubleOther = insoluble in organic solvents | RefractIndex = 1.482 }} |Section3={{Chembox Hazards | ExternalSDS = hazard.com | MainHazards = Irritant | SPhrases = {{S24/25}} | LD50 = 3.053 g kg−1 }} |Section4={{Chembox Related | OtherAnions = Trisodium phosphate Tetrasodium pyrophosphate Pentasodium triphosphate | OtherCompounds = Sodium trimetaphosphate }} }} Sodium hexametaphosphate (SHMP) is a hexamer of composition (NaPO3)6.[2] Sodium hexametaphosphate of commerce is typically a mixture of polymeric metaphosphates, of which the hexamer is one, and is usually the compound referred to by this name. It is more correctly termed sodium polymetaphosphate. UsesSHMP is used as a sequestrant and has applications within a wide variety of industries, including as a food additive in which it is used under the E number E452i. Sodium carbonate is sometimes added to SHMP to raise the pH to 8.0–8.6, which produces a number of SHMP products used for water softening and detergents. A significant use for sodium hexametaphosphate is as a deflocculant in the production of clay-based ceramic particles.[3][4][5][6] It is also used as a dispersing agent to break down clay and other soil types for soil texture assessment.[7] It is used as an active ingredient in toothpastes as an anti-staining and tartar prevention ingredient.[8] Food additiveAs a food additive, SHMP is used as an emulsifier. Artificial maple syrup, canned milk, cheese powders and dips, imitation cheese, whipped topping, packaged egg whites, roast beef, fish fillets, fruit jelly, frozen desserts, salad dressing, herring, breakfast cereal, ice cream, beer, and bottled beverages, among other foods, can contain SHMP.[9][10][11] PreparationSHMP is prepared by heating monosodium orthophosphate to generate sodium acid pyrophosphate: 2 NaH2PO4 → Na2H2P2O7 + H2O Subsequently, the pyrophosphate is heated to give the corresponding sodium hexametaphosphate: 3 Na2H2P2O7 → (NaPO3)6 + 3 H2O followed by rapid cooling. ReactionsSHMP hydrolyzes in aqueous solution, particularly under acidic conditions, to sodium trimetaphosphate and sodium orthophosphate.[12] HistoryHexametaphosphoric acid was named (but misidentified) in 1849 by the German chemist Theodor Fleitmann (1828–1904).[13][14] By 1956, chromatographic analysis of hydrolysates of Graham's salt (sodium polyphosphate) indicated the presence of cyclic anions containing more than four phosphate groups;[15] these findings were confirmed in 1961.[16] In 1963, the German chemists Erich Thilo and Ulrich Schülke succeeded in preparing sodium hexametaphosphate by heating anhydrous sodium trimetaphosphate.[17] References1. ^Merck Index, 12th Edition, Sodium polymetaphosphate, 8814 2. ^Van Wazer, John R. Phosphorus and its compounds. New York : Interscience Publishers (1958) 3. ^The Role Of Sodium Hexametaphosphate In The Dissolution Process Of Kaolinite And KaolinF. Andreola; E.Castellini; T.Manfredini; M.Romagnoli. Journal of the European Ceramic Society, Volume 24, Number 7, June 2004. 4. ^Impact Of Dispersants On The Mechanical Strength Development Of Alumina-Spinel Self-Flowing Refractory Castables. Sasan Otroj, Mohammad Reza Nilforushan, Arash Daghighi, Reza Marzban. Ceramics – Silikáty 54 (3) 284–289 (2010) 5. ^Effect Of Adding Sodium Hexametaphosphate Liquefier On Basic Properties Of Calcium Phosphate Cements. S. Hesaraki; A. Zamanian; F. Moztarzadeh. Journal of Biomedical Materials Research Part A. Vol. 88A, No. 2, 2009 6. ^Study Of Clay’s Mineralogy Effect On Rheological Behavior Of Ceramic Suspensions Using An Experimental Design. Afef Jmal Ayadi; Julien Soro; Amel Kamoun; Samir Baklouti. International Journal of Recent Research and Applied Studies 14 (2). February 2013. 7. ^ASTM D422 – 63(2007) Standard Test Method for Particle-Size Analysis of Soils. 8. ^Crest Pro-Health Frequently Asked Questions 9. ^{{cite web | url=http://www.befoodsmart.com/ingredients/sodium-hexametaphosphate.php | title=Ingredient Results - Sodium Hexametaphosphate}} 10. ^{{cite web | url=http://www.fda.gov/food/ingredientspackaginglabeling/foodadditivesingredients/ucm091048.htm | title=Food Additives & Ingredients - Food Additive Status List}} 11. ^{{cite web | url=http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=173.310 | title=CFR - Code of Federal Regulations Title 21}} 12. ^{{cite book|last1=Van Wazer|first1=John|title=Phosphorus and its Compounds|date=1958|publisher=Interscience Publishers|location=New York|url=http://catalog.hathitrust.org/Record/010058734|accessdate=7 April 2015}} 13. ^{{cite journal |last1=Fleitmann |first1=Th. |title=Ueber die verschiedenen Metaphosphorsäuren und zwei neue Säuren derselben Verbindungsproportion |journal=Annalen der Physik und Chemie |date=1849 |volume=78 |pages=233–260, 338–366 |url=https://babel.hathitrust.org/cgi/pt?id=umn.31951d00321228n;view=1up;seq=251 |series=2nd series |trans-title=On various metaphosphoric acids and two new acids of the same compound proportion |language=German}} On p. 249, Fleitmann coined the name Hexametaphosphorsäure (hexametaphosphoric acid). 14. ^{{cite journal |last1=Griffith |first1=E.J. |last2=Buxton |first2=R.L. |title=The preparation and properties of the twelve-membered ring hexametaphosphate anion |journal=Inorganic Chemistry |date=1965 |volume=4 |issue=4 |pages=549–551}} ; see p. 549. 15. ^{{cite journal |last1=Van Wazer |first1=J. R. |last2=Kroupa |first2=E. Karl |title=Existence of ring phosphates higher than tetrametaphosphate |journal=Journal of the American Chemical Society |date=1956 |volume=78 |issue=8 |page=1772}} 16. ^(Thilo & Schülke, 1963a), p. 1175. 17. ^See* {{cite journal |last1=Thilo |first1=E. |last2=Schülke |first2=U. |title=Darstellung des echten Natrium-hexametaphosphates Na6[P6O18] |journal=Angewandte Chemie |date=1963a |volume=75 |issue=23 |pages=1175–1176 |trans-title=Preparation of true sodium hexametaphosphate Na6[P6O18] |language=German}}* {{cite journal |last1=Thilo |first1=E. |last2=Schülke |first2=U. |title=Preparation of true sodium hexametaphosphate Na6[P6O18] |journal=Angewandte Chemie International Edition |date=1963b |volume=2 |issue=12 |page=742 }} External links
5 : Sodium compounds|Phosphates|Water treatment|Photographic chemicals|Glass compositions |
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