聚丙烯酸鈉畢業(yè)論文外文翻譯

1、外文文獻原稿和譯文外文文獻原稿和譯文SodiumPolyacrylate:Alsoknownassuperabsbent“SAP”(superabsbentpolymer)KimberlyClarkusedtocallitSAM(superabsbentmaterial).Itistypicallyusedinfinegranularfm(liketablesalt).Ithelpsimprovecapacityfbetterreten

2、tioninadisposablediaperallowingtheproducttobethinnerwithimprovedperfmancelessusageofpinefluffpulp.Themolecularstructureofthepolyacrylatehassodiumcarboxylategroupshangingoffthemainchain.Whenitcomesincontactwithwaterthesod

3、iumdetachesitselfleavingonlycarboxylions.Beingnegativelygedtheseionsrepeloneanothersothatthepolymeralsohascrosslinkswhicheffectivelyleadstoathreedimensionalstructure.Ithashigemolecularweightofmethanamillionthusinsteadofg

4、ettingdissolveditsolidifiesintoagel.TheHydrogeninthewater(HOH)istrappedbytheacrylateduetotheatomicbondsassociatedwiththepolarityfcesbetweentheatoms.Electrolytesintheliquidsuchassaltminerals(urinecontains0.9%ofminerals)re

5、ducepolaritytherebyaffectingsuperabsbentpropertiesespeciallywithregardtothesuperabsbentcapacityfliquidretention.ThisisthemainreasonwhydiaperscontainingSAPshouldneverbetestedwithplainwater.Linearmolecularconfigurationshav

6、elesstotalcapacitythannonlinearmoleculesbutontheotherhretentionofliquidinalinearmoleculeishigherthaninanonlinearmoleculeduetoimprovedpolarity.FalistofSAPsupplierspleaseusethislink:SAPthesuperabsbentcanbedesignedtoabsbhig

7、heramountsofliquids(withlessretention)veryhighretentions(butlowercapacity).Inadditionasurfacecrosslinkercanbeaddedtothesuperabsbentparticletohelpitmoveliquidswhileitissaturated.Thishelpsavoidfmationof“gelblocks“thephenom

8、enonthatdescribestheimpossibilityofmovingliquidsonceaSAPparticlegetssaturated.HistyofSuperAbsbentPolymerChemistryUntilthe1980’swaterabsbingmaterialswerecellulosicfiberbasedproducts.Choicesweretissuepapercottonspongefluff

9、pulp.Thewaterretentioncapacityofthesetypesofmaterialsisonly20timestheirweight–atmost.Intheearly1960stheUnitedStatesDepartmentofAgriculture(USDA)wasconductingwkonmaterialstoimprovewaterconservationinsoils.Theydevelopedare

10、sinbasedonthegraftingofacrylonitrilepolymerontothebackboneofstarchmolecules(i.e.starchgrafting).Thehydrolyzedproductofthehydrolysisofthisstarchacrylonitrilecopolymergavewaterabsptiongreaterthan400timesitsabsbentstypicall

11、yarecrosslinkedacrylichomopolymers(usuallySodiumneutralized).Superabsbentsusedinsoilamendmentsapplicationstendtobecrosslinkedacrylicacrylaecopolymers(usuallyPotassiumneutralized).BesidesgranularsuperabsbentpolymersARCOCh

12、emicaldevelopedasuperabsbentfibertechnologyintheearly1990s.ThistechnologywaseventuallysoldtoCamelotAbsbents.Therearesuperabsbentfiberscommerciallyavailabletoday.Whilesignificantlymeexpensivethanthegranularpolymersthesupe

13、rabsbentfibersoffertechnicaladvantagesincertainnichemarketsincludingcablewrapmedicaldevicesfoodpackaging.Sodiumpolyacrylatealsoknownaswaterlockisapolymerwiththechemicalfmula[CH2CH(COONa)]nwidelyusedinconsumerproducts.Ith

14、astheabilitytoabsbasmuchas200to300timesitsmassinwater.Acrylatepolymersgenerallyareconsideredtopossessananionicge.Whilesodiumneutralizedpolyacrylatesarethemostcommonfmusedinindustrytherearealsoothersaltsavailableincluding

15、potassiumlithiumammonium.ApplicationsAcrylatesacrylicchemistryhaveawidevarietyofindustrialusesthatinclude:?Sequesteringagentsindetergents.(Bybindinghardwaterelementssuchascalciummagnesiumthesurfactantsindetergentswkmeeff

16、iciently.)?Thickeningagents?Coatings?FakesnowSuperabsbentpolymers.Thesecrosslinkedacrylicpolymersarereferredtoas“SuperAbsbents““WaterCrystals“areusedinbabydiapers.Copolymerversionsareusedinagricultureotherspecialtyabsben