pan基碳纤维制备过程中微纳结构演变与发展

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1、北京化丁人学顺．Ij学位论义structureinPANfiberswasalsobeenusedaswellasPorodtheorem．Theestablishedmethodhasacontributiontothesystemofthecharacterizationtechniqueforrevealingthefeaturestructureformationandinheritingevolutionduringthewet—spinningprocessofPANprecursorandthethermalstabilization

2、processofPANbasedcarbonfiber．Theresultsofthisthesisindicatedthat：(1)BasedontheSAXSmeasurement，thereexistsakindofcharacteristiclongperiodstructurewiththesizeof47．6nminthecoagulationfiber．Combiningwiththecorrelationfunctionanalysis，thedetailstructuralparameterssuchasthelengthofl

3、ongperiod，thethicknessofcrystallineandamorphousregionsforPANfiberwereobtained．Amodelofthelongperiodmicrostructureunit-cellwasproposedaccordingtotheexperimentdata．Withtheprocessingofthecoagulationprocess，thelengthoflongperiodisdecreasedbecauseofthefoldingofthePANmolecularchains

4、．Afterthestretchingundertension，theSAXSintensityofthelongperiodstructurebecameweak，whichindicatedthatthehighorderstructuregraduallytendtobehomogeneous．Asfortheprecursor,longperiodstructuresalmostdisappeared．(2)AccordingthesimultaneousmeasurementsofSAXSandWAXDduringheattreatmen

5、tforthesimulationofthermalstabilizationprocessofPANfiber,duetochemicalcyclizationreactionsinthefiber,atthetemperatureof2000C，thelamellarstructurewhichthesizeisabout7．5rimappearedandgraduallybecamemoreobviouswithaboutthesamesizewithincreasingtemperatureupto240。C．Athighertempera

6、ture，thedomainwasgraduallychangedtothearomaticcyclizedstructure，thescatteringsignalwasweakenedduetothehomogenizationofinnerstructure．(3)Inthepreparationprocessofwet—spinningforPANprecursor,the摘要statisticalcontentanddimensionofmicro-voidstructurewasreduced，anditsstatisticdimens

7、ionwasalsodecreased．Themicro—voidlengthalongthefiberaxiswasmaintainedaroundacertainsize．Intheprocessofstabilizationstage，withtheincreasingoftemperature，thestatisticalcontentanddimensionofmicro—voidstructurehasatendencyofdecreasingbeforeincreasing．Onthebasisofthesestudies，Aanal

8、ysismethodofmicro—nanostructureinPANfiberswassuccessfullyesta