Physical Properties of Main-Chain Liquid Crystalline Polyurethanes

碩士 === 元智大學 === 化學工程學系 === 91 === In this study, we report physical properties of main-chain liquid crystalline polyurethanes. Thermotropic hard segment type liquid crystalline polyurethanes can be obtained by a step polyaddition reaction from mesogenic diols with diisocyanates. All the t...

Full description

Bibliographic Details
Main Authors: Piao-Fu Chang, 張標富
Other Authors: T.L. Yu
Format: Others
Language:zh-TW
Published: 2003
Online Access:http://ndltd.ncl.edu.tw/handle/99726372720964243800
id ndltd-TW-091YZU00063001
record_format oai_dc
spelling ndltd-TW-091YZU000630012015-10-13T13:39:20Z http://ndltd.ncl.edu.tw/handle/99726372720964243800 Physical Properties of Main-Chain Liquid Crystalline Polyurethanes 主鏈含液晶分子之聚氨基甲酸酯物理性質 Piao-Fu Chang 張標富 碩士 元智大學 化學工程學系 91 In this study, we report physical properties of main-chain liquid crystalline polyurethanes. Thermotropic hard segment type liquid crystalline polyurethanes can be obtained by a step polyaddition reaction from mesogenic diols with diisocyanates. All the thermal decomposition behavior of polyurethanes are about 300℃. It shows that the technical application of polyurethanes is limited. In order to obtain polymers with a high application we became interested in the study of decrease of the hard segment melting points to enhance mesogenic temperature range △TLC (i.e. △TLC =Tm→TN-I). Phase segregation of polyurethanes was investigate by DSC, FTIR and POM. It was found that the temperatures of phase transitions depend on the amount of mesogenic diols substituted for 1,4-BD. They show a higher transition temperature (Tg and Tm) when the polyurethanes have been raised by the increase of the amount of mesogenic diols. The transition temperatures and the temperature ranges of mesophases also changed with the length of alkoxy spacer and the kind of diisocyanate. The longer the spacer length, the lower is the transition temperature. And MDIn shows a higher Td than that of TDIn. T.L. Yu 余子隆 2003 學位論文 ; thesis 69 zh-TW
collection NDLTD
language zh-TW
format Others
sources NDLTD
description 碩士 === 元智大學 === 化學工程學系 === 91 === In this study, we report physical properties of main-chain liquid crystalline polyurethanes. Thermotropic hard segment type liquid crystalline polyurethanes can be obtained by a step polyaddition reaction from mesogenic diols with diisocyanates. All the thermal decomposition behavior of polyurethanes are about 300℃. It shows that the technical application of polyurethanes is limited. In order to obtain polymers with a high application we became interested in the study of decrease of the hard segment melting points to enhance mesogenic temperature range △TLC (i.e. △TLC =Tm→TN-I). Phase segregation of polyurethanes was investigate by DSC, FTIR and POM. It was found that the temperatures of phase transitions depend on the amount of mesogenic diols substituted for 1,4-BD. They show a higher transition temperature (Tg and Tm) when the polyurethanes have been raised by the increase of the amount of mesogenic diols. The transition temperatures and the temperature ranges of mesophases also changed with the length of alkoxy spacer and the kind of diisocyanate. The longer the spacer length, the lower is the transition temperature. And MDIn shows a higher Td than that of TDIn.
author2 T.L. Yu
author_facet T.L. Yu
Piao-Fu Chang
張標富
author Piao-Fu Chang
張標富
spellingShingle Piao-Fu Chang
張標富
Physical Properties of Main-Chain Liquid Crystalline Polyurethanes
author_sort Piao-Fu Chang
title Physical Properties of Main-Chain Liquid Crystalline Polyurethanes
title_short Physical Properties of Main-Chain Liquid Crystalline Polyurethanes
title_full Physical Properties of Main-Chain Liquid Crystalline Polyurethanes
title_fullStr Physical Properties of Main-Chain Liquid Crystalline Polyurethanes
title_full_unstemmed Physical Properties of Main-Chain Liquid Crystalline Polyurethanes
title_sort physical properties of main-chain liquid crystalline polyurethanes
publishDate 2003
url http://ndltd.ncl.edu.tw/handle/99726372720964243800
work_keys_str_mv AT piaofuchang physicalpropertiesofmainchainliquidcrystallinepolyurethanes
AT zhāngbiāofù physicalpropertiesofmainchainliquidcrystallinepolyurethanes
AT piaofuchang zhǔliànhányèjīngfēnzizhījùānjījiǎsuānzhǐwùlǐxìngzhì
AT zhāngbiāofù zhǔliànhányèjīngfēnzizhījùānjījiǎsuānzhǐwùlǐxìngzhì
_version_ 1717739410054709248