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1、功能性液晶單體的合成、熱性能及光聚合反應(yīng)的研究摘要功能性液晶單體具有液晶小分子的自組裝性能,同時(shí)還可在紫外光輻照下發(fā)生化學(xué)反應(yīng)從而改變材料結(jié)構(gòu)以及光電等性能,因此在光電信息存儲(chǔ)、液晶顯示等領(lǐng)域有著潛在的應(yīng)用前景。本課題中設(shè)計(jì)并合成了三種具有光敏基團(tuán)的液晶單體,它們所包含的光敏基團(tuán)為:M1為丙烯酸酯、M2同時(shí)具有丙烯酸酯及肉桂酸酯、M3為肉桂酸酯。利用紅外光譜(FT-IR)以及核磁共振氫譜(1HNMR)對(duì)它們的結(jié)構(gòu)進(jìn)行了分析表征;并利用差失量熱掃描(DSC)及偏光顯微鏡(POM)對(duì)功能性液晶單體的熱性能進(jìn)行分析,結(jié)果表明它
2、們均可在加熱過(guò)程中形成液晶相。同時(shí),具有肉桂酸酯基團(tuán)的M3在紫外光輻照下可發(fā)生光二聚反應(yīng)生成二聚物Dimer,二者的液晶相并未有明顯差異。采用熱引發(fā)自由基聚合的方式將單體M2的丙烯酸酯基團(tuán)聚合,得到結(jié)構(gòu)中具有肉桂酸酯基團(tuán)的聚合物P2。利用實(shí)時(shí)紅外的方法檢測(cè)各物質(zhì)的光聚合反應(yīng)的動(dòng)力學(xué)。并用廣角X射線(xiàn)衍射(WXRD)分析各物質(zhì)的組裝方式。結(jié)果表明自由基光引發(fā)劑的存在降低了M3中肉桂酸酯光二聚反應(yīng)的速率;當(dāng)分子排列有序而規(guī)整時(shí),光二聚的反應(yīng)速率快,同時(shí)其轉(zhuǎn)化率是輻照能量的函數(shù);反之,光二聚的反應(yīng)速率慢,同時(shí)當(dāng)輻照能量一定時(shí),反
3、應(yīng)轉(zhuǎn)化率隨光強(qiáng)的增大而增大·關(guān)鍵詞:液晶,光敏基團(tuán),光二聚,肉桂酸酯基團(tuán)ABSTRACTSTUDYoNSYNTHESIS,THERMALPRoPERTIESANDPHoToPoLYMERIZATIoNoFFUNCTIoNALLIQUIDCRYSTALLINEMoNoMERSFunctionalliquidcrystallinemonomers(FLCMs)assembleasliquidcrystallinemolecules.Meanwhile,underultravioletradiationtheirstructu
4、resandelectricalandopticalpropertiesalechanged.Therefore,F(xiàn)LCMshaveversatilepotentialapplicationsandthushaveattractedmuchattention.Inthisstudy,threeFLCMsweresynthesizedwhosestructureswereconfirmedbyFT—IRand1HNMRspectra.Theirstructuresincluderigidityparts,flexibles
5、pacersandphotosensitivegroupswhichaleacrylate,andcinnamoylmoieties.TheirthermalpropertiesweremeasuredbyDSCandPOMandresultsindicatesthatallofthemcouldformliquidcrystallinephaseduringheatingprocess.Besides,photodimerizationdidnothaveobviouseffectstotheliquidcrystal
6、phaseofthemonomercontainingcinnamoylmoieties.Moreover,P2WasobtainedbypolymerizationofacrylicgroupofME.DifferentkineticbehaviorsinphotodimerizationbetweenM2andP2werestudiedbyrealtimeFT-IRandWXRD.Resultsdemonstratedthattheexistenceoffreeradicalphotoinitiatordelayed
7、photodimerizationofM3.Besides,photodimerizationoccursfasterinanordermoleculararrangementthaninarandomone.Theconversionoftrans—vinyleneinthecinnamoylmoietyofM3isthefunctionofexposureenergy.ForP2,underthesameexposureenergy,increaseinlightintensityalsocauseincreasei
8、nconversion.KEYWORDS:liquidcrystals,F(xiàn)unctionalgroups,photodimerization,cinnamoylmoietiesIII北京化工大學(xué)位論文原創(chuàng)性聲明本人鄭重聲明:所呈交的學(xué)位論文,是本人在導(dǎo)師的指導(dǎo)下,獨(dú)立進(jìn)行研究工作所取得的成果。除文中已經(jīng)注明引用的內(nèi)容