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环氧乙烷和环氧丙烷开环聚合的研究.docx

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环氧乙烷和环氧丙烷开环聚合的研究 Title:ResearchonRing-OpeningPolymerizationofEthyleneOxideandPropyleneOxide Abstract: Ring-openingpolymerizationisaversatiletechniquethatallowsthesynthesisofvariouspolymericmaterialswithuniqueproperties.Thispaperaimstoexplorethering-openingpolymerizationofethyleneoxideandpropyleneoxideandsummarizekeyfindingsandadvancementsinthisareaofresearch.Thepaperdiscussesthereactionmechanism,catalystsystems,polymerizationparameters,andtheresultingpropertiesoftheobtainedpolymers.Additionally,ithighlightsthepotentialapplicationsandfutureprospectsofthesepolymersinvariousfields. 1.Introduction Ring-openingpolymerizationisamethodthatinvolvestheopeningofcyclicmonomers,resultingintheformationofalongchainpolymer.Theuseofethyleneoxide(EO)andpropyleneoxide(PO)monomersinring-openingpolymerizationhasattractedsignificantinterestduetotheuniquepropertiesoftheresultingpolymers.Thispaperaimstoprovideanoverviewofthecurrentstateofresearchonthering-openingpolymerizationofEOandPO. 2.ReactionMechanism Thering-openingpolymerizationofEOandPOcanoccurthroughcationic,anionic,orcoordinationmechanisms.ThecationicmechanismismostcommonlyusedandinvolvesthereactionofaLewisacidcatalystwiththeetheroxygenofthemonomer,leadingtotheformationofacarbocationinitiators.Subsequentpropagationreactionsoccurbytheattackofthemonomeronthecarbocation,resultinginthegrowthofthepolymerchain.Theanionicandcoordinationmechanismsinvolvetheuseofstrongbasesorcoordinationcatalysts,respectively. 3.CatalystSystems Variouscatalystsystemshavebeenemployedforthering-openingpolymerizationofEOandPO.Forexample,Lewisacidssuchasborontrifluoride(BF3)andaluminumtrichloride(AlCl3)havebeenusedincationicpolymerizations.Initiatorssuchasalcoholsandamineshavealsobeenutilized.Inanionicpolymerizations,alkalimetalalkoxidesandalkalimetalamideshavebeenemployedasinitiators.Coordinationcatalysts,suchastitaniumcomplexes,haveshownpromisingresultsincoordinationpolymerizations.Thechoiceofcatalystsystemdependsonthedesiredpropertiesandapplicationsofther