,Synthesis and properties of liquid crystalline polyurethanes

来源 :中国高等学校学术文摘·化学 | 被引量 : 0次 | 上传用户:sqno1
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
1,4-Bis(p-hydroxybenzoate)phenylene was prepared using 1,4-bis(trimethylsiloxy)benzene and p-hydroxybenzoyl chloride as starting materials.A series of novel 1,4-bis(p-hydroxyalkoxybenzoate)phenylene were synthesized by reaction of 1,4-bis(p-hydroxybenzoate)phenylene with 3-bromopropanol and 4-bromobutanol,respectively,The liquid crystal polyurethanes were prepared by 1,4-bis(p-hydroxyalkoxybenzoate)phenylene with MDI (p-methylene diphenylenediisocyanate) and 2,4-TDI(2,4-toluenediisocyanate),respectively.The thermotropic properties,the melting point (Tm) and the isotropization temperature (Ti) of the synthesized polyurethanes were characterized by DSC,IR and POM.It showed that all of the polyurethane polymers exhibited thermotropic liquid crystalline properties between 144℃ and 260℃.The transition temperature (Tm and Ti) decreased with an increase in the length of the methylene spacer.
其他文献
Starting from pyridine-2,6-dicarboxylic acid (DPA),a series of novel pyridine-2,6-dicarboxylic acid derivatives were synthesized.In these compounds,4-(hydroxyme
本试验于2005~2006年在山东农业大学农学试验站进行。试验选用济麦20(JM20)和山农1391(SN1391)两小麦品种,在小麦开花后不同时期,即灌浆前期(花后6~9d、S1)、中期(花后16~19d、S2)、后期(花后26~29d、S3),于大田条件下利用透光率为10%黑色遮荫网模拟弱光照天气,研究弱光对小麦产量及淀粉品质形成的影响及其生理生化机制,主要研究结果如下:1.花后弱光对小麦产量
This work attempts to calculate the binding-site number using fluorescence spectroscopic method with bovine serum albumin (BSA) and Indo-1 as proteinand ligand
广场舞是作为群众舞蹈中的一种,它一项最平民、最草根、最广泛的群众文化活动,近年来在城乡广大地区蓬勃兴起,成为了一道靓丽的文化风景。其集健身和娱乐功能于一体,在丰富群
This paper reports the preparation of crosslinked core-shell poly(butyl acrylate )/polystyrene (PBA/PS)and poly(butyl acrylate)/poly(methyl methacrylate) (PBA/P
A homologous series of first- to third-generation dendritic polyamides 2a,3,and 5 with tris(aminoethyl)amine (TREA) as the core and the protected amino function
本研究利用小麦基因芯片比较转GmDREB1基因的小麦株系08T349和受体小麦济麦19在正常生长条件下的全基因组表达谱的变化,初步确定了在转基因小麦中受GmDREB1基因控制的下游基因。测定在干旱条件下转GmDREB1基因小麦和受体小麦的生理指标的变化,根据基因芯片分析结果及各种生理指标的检测结果初步分析了GmDREB1基因提高转基因小麦抗逆性的分子机制及生理机制。利用基因芯片的结果,采取基因表达
Photochemical reaction of C60 with iminodiacetic ester (NH(CH2COOR)2,R=Me,Et,t-Bu) produced fulleropyrrolidine derivatives 2 in a 55%-36% yield (based on consum
The solid fast ionic conductor was synthesized by the sol-gel-hydrothermal method.The influences of the dispersion reagent,the alkalinity and the calcination te
An investigation of the copolymerization of allylgly cidyl ether (AGE) with methyl acrylate (MA) was per-formed in the presence of benzyl imidazole-1-carbodithi