表面修飾聚氧化乙烯粒子的結晶過程研究.pdf

1、天津工業(yè)大學碩士學位論文表面修飾聚氧化乙烯粒子的結晶過程研究姓名：宋正紅申請學位級別：碩士專業(yè)：材料學指導教師：張志英20061201AbstractAbstractTheimprovedWurstcrequipmentwasdesignedonthebaseoftheprincipleoftheWuesterequipmentOnthisequipment，thepolyethyleneglycol(PEO)particleswere

2、modifiedbythemethodoffluidizedcoatingPEOparticleswereusedasthecoreandtheEthylCellulose正oasthesurfaceWeresearchedthecrystallizationofthedifferentmolarmassPEOparticles，includingtheisothermalcrystallizationandnon—isothermal

3、crystallizationofthePEOparticlesWetrytoprobeintoanewequationthatissuitableforthecoolingprocessofthelionisothermalcrystallizationTheresultshowsthattheimprovedWursterequipmentisquitesuitableformakingthesurfacemodifiedPEOpa

4、rticlesThecontentandthethicknessofthesurfacemodifiedPEO’wallCallbeobtainedbyusingthemeltingheatorthecrystallizationheatanalysisinvasethatthesurfacematerialsisnoheateffectinthetemperaturerangeofphasechangeofthePEOparticel

5、sThethicknessobtainedfromtheofphasechangeisconsistentwiththeoneobtainedfiomtheopticalmicroscopeThecrystallizationofthesurfacemodifiedPEOparticlesendsincasethatthefrontsofthesphemlitesinthesurfacemodifiedPEOparticlesarriv

6、ethewalluntilthespherulitiesfilledtheconfinedvolumeButthefrontsofthespherulitesinoriginalPEOparticlesarelikelytoreachinsideofadjacentPEOparticlesowingtoconglutinationPEOparticlesaftermeltedThehalftimesofthecrystallizatio

7、nandthefastesttimeofthecrystallizationofthesurfacemodifiedPEOparticlesareshorterthanthoseoftheoriginalPEOparticlesThecrystallizationpeakpositionofthesurfacemodifiedPEOparticlesshiftstohighertemperatureinCasethatthePEOpar

8、ticles’diameterislessthan400佃ThetimofthePEOparticlescrystallizationWaslongerastheisothermaltemperatureincreased；Thettt2ofthePEOparticlescrystallizationislargerwiththemolarmassofthePEOincreasingThesporadicnucleationbrings

9、ontwocrystallizationpeaksappearintheDSCOlIVesUnderthenonisothermalcrystallizationprocess，thetl，2ofthePEOparticleswereshorterasthecoolingrateincreasingtheheatofthecrystallizationincreasesTheAvramiexponentniscloseto3whichi

10、sindependentthecoolingratesBycontrastingthesurfacemodifiedPEOparticlestotheorignalPEOparticles，thespeedconstantofthecrystallizationofthesurfacemodifiedPEOparticlesWassmallerinthefirststageofcrystallization，butlargerlater