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1、GeorgesMK,etal.(XeroxResearchCenterofCanada)Macromolecules,1993,36,2987-29881.NMP的發(fā)現(xiàn)及歷史：2,2,4,4-四甲基派啶氮氧穩(wěn)定自由基 (2,2,4,4-tetramethyl-1-piperidinyloxy,TEMPO)1.NMP的發(fā)現(xiàn)及歷史：自由基捕獲劑、阻聚劑、抗老化劑、熱降解抑制劑和熱穩(wěn)定劑等。相對TD，其活性更低，不能引發(fā)聚合，且與苯乙烯增長鏈末端結(jié)合的鍵更弱。分子量與轉(zhuǎn)化率間線性關(guān)系！TEMPO/BPO比例對聚合的影響！1.NMP的發(fā)現(xiàn)及歷史：1.NMP的發(fā)現(xiàn)及歷史：Manysubse
2、quentstudieshaveconfirmedGeorgesfindingsandhavealsoshownthatincreasingthemolarratioofnitroxidetoinitiatorresultinslowerreactions,lowerPDIs,andlowermolecularweightpolymers.Asacomparison,Georgesperformedasuspensioncopolymerizationofstyreneandbutadienewith(a)andwithout(b)TEMPO.ThePDIofthepolymer
3、withTEMPOwas1.36whilethePDIofthepolymerwithoutTEMPOwas4.61.J.Am.Chem.SOC.1994,116,11185-11186SOLOMON八十年代的工作：用穩(wěn)定自由基封端研究St、MMA關(guān)于引發(fā)和終止的結(jié)構(gòu)SOLOMON八十年代的工作：SOLOMON八十年代的工作：1.NMP的發(fā)現(xiàn)及歷史：Rizzardo等與TEMPO/SFRP失之交臂？溫度低，分布寬thetermliving,controlledandstepgrowthwereused.雙分子體系BPO:TEMPO=1:1.3Poorlydefinednature
4、oftheinitiatingspecies單分子體系(Unimolecular)：單分子體系可控效果優(yōu)于雙分子體系！Typicallythesepropagatingcarboncenteredradicalsaretransientspecies,tendtodisappearbyself-termination,whichistypicallyadiffusioncontrolledprocess.Thisraisesthequestion,whydoweonlyseeminoramountsofirreversibleterminationinNMP?2.NMP的聚合機(jī)理
5、2.NMP的聚合機(jī)理2.1平衡的建立：persistentradicaleffectR·活潑自由基，Y·persistentradical,產(chǎn)物只有一種R·,Y·活潑自由基，則產(chǎn)物有三種,1:2:1。2.NMP的聚合機(jī)理2.1平衡的建立：persistentradicaleffect2.NMP的聚合機(jī)理2.1平衡的建立：persistentradicaleffect2.1平衡的建立：persistentradicaleffectThestableradical(6)iscapableofreactionwitheither(2)or(4)butnotitself.Duetothe
6、factthatirreversibleterminationwilloccurbetweenactiveradicalstheconcentrationofthestableradicalpresentwillincrease.Duetothebuildupinconcentrationof(6),verylittlecouplingproductsbetweenactiveradicals(2)-(2),(2)-(4),or(4)-(4)areformed,astheactiveradicalsreactalmostexclusivelywiththestableorpers
7、istentradical(6).2.1平衡的建立：persistentradicaleffectThePersistentRadicalEffect:APrincipleforSelectiveRadicalReactionsandLivingRadicalPolymerizationsChem.Rev.2001,101,3581-3610HannsFischer2.NMP的聚合機(jī)理Radicals(2)and(4)arepresentatverylowconcentratio
