DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Shim, Sang-Chul | - |
dc.contributor.advisor | 심상철 | - |
dc.contributor.author | Kim, Jin-Young | - |
dc.contributor.author | 김진영 | - |
dc.date.accessioned | 2011-12-13T04:47:59Z | - |
dc.date.available | 2011-12-13T04:47:59Z | - |
dc.date.issued | 2001 | - |
dc.identifier.uri | http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=165478&flag=dissertation | - |
dc.identifier.uri | http://hdl.handle.net/10203/31872 | - |
dc.description | 학위논문(석사) - 한국과학기술원 : 화학과, 2001.2, [ vi, 43 p. ] | - |
dc.description.abstract | A series of combined liquid-crystalline polymers based on 4,4``-biphenyl, terephthalate with two symmetric mesogenic groups and methylene flexible spacers, denoted as P-n, have been prepared from 2,5-bis(n-(4``-methoxy biphenyl-4-yloxy)alkyloxy)terephthalyl chloride (n=2,6,10) and 4,4``-bis(6-hydroxyhexoxy) biphenyl [BHHBP] by condensation method. The thermal properties of polymers were characterized using DSC and its mesophase structure was confirmed by the polarized optical microscopic (POM) study and X-ray measurements. The polymers P-2 and P-6 show two endothermic peaks on heating and two exothermic peaks on cooling: at the first transition, the solid crystalline is turned into fluid liquid crystalline phase, and at the second transition, the materials entered into the isotropic phase. P-2 and P-6 with same or short length of methylene units in side chain spacer than that of main chain exhibited an enantiotropic liquid crystalline phase. In trimer and P-10 with longer length of methylene units in side chain spacer than that of main chain , they did not show the mesophase. All the polymers were crystalline at room temperature. P-2 and P-6 with even numbers of methylene units in spacers were transformed from crystalline solid directly into liquid-crystalline phase at 131.2℃ and 121.0℃ respectively, exhibited a smectic phase at 32℃ and 28℃ mesophase temperature. The X-ray diffraction pattern of the polymer P-6 exhibited a broad diffraction in small-angle region around q = 2.47 (50.9Å) indicating that mesophase formed by the polymer P-6 is smectic phase. This means that the side mesogenic groups are arranged perpendicular to the backbone in the mesophase and also tend to align themselves in layers. | eng |
dc.language | eng | - |
dc.publisher | 한국과학기술원 | - |
dc.subject | polymer | - |
dc.subject | liquid crystal | - |
dc.subject | combined | - |
dc.subject | x-ray | - |
dc.subject | X선 회절 | - |
dc.subject | 고분자 | - |
dc.subject | 스멕틱 | - |
dc.subject | 액정 | - |
dc.subject | 결합된 형태 | - |
dc.title | Synthesis and properties of combined liquid-crystalline polymers with two symmetric mesogene units in the side-chain | - |
dc.title.alternative | 대칭 곁사슬 측쇄기를 가진 복합형 액정 고분자의 합성 및 특성 연구 | - |
dc.type | Thesis(Master) | - |
dc.identifier.CNRN | 165478/325007 | - |
dc.description.department | 한국과학기술원 : 화학과, | - |
dc.identifier.uid | 000993162 | - |
dc.contributor.localauthor | Shim, Sang-Chul | - |
dc.contributor.localauthor | 심상철 | - |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.