新型希夫碱型液晶超分子化合物的合成和表征

通过醚化、还原、缩合及酯化等反应,合成了以4-[((4-己烷氧苯基)亚氨基)甲基]苯基异烟酸酯为质子受体,烷氧基苯甲酸为质子供体,氢键为链接基的希夫碱型超分子液晶化合物。用IR、1H NMR对中间体及其产物进行了结构表征,并用热台偏光显微镜分别对目标产物的液晶行为进行了研究。通过IR对羧基和吡啶环间分子间氢键的形成进行了验证,通过偏光显微镜说明氢键复合物是典型的热致液晶且呈现近晶相和向列相两种相态,并且复合物较质子供体和受体的液晶相范围宽,说明分子间氢键起到了稳定液晶相态的作用。     

光致变色聚硅氧烷液晶高分子的合成及液晶行为

通过取代、还原、重氮化和偶合等反应,合成了一种新的光致变色液晶单体4-丁氧基-4′-十一烯-[10]-酰氧基偶氮苯,并与聚(甲基氢硅氧烷)通过硅氢加成生成一种新的光致变色高分子液晶。通过^1H NMR和IR对单体和聚合物的结构进行了表征,并证实了聚合物的硅氢化程度近于完全。通过DSC和热台偏光显微镜(POM)对单体和聚合物的液晶行为进行了研究,证明了都具有液晶性。     

侧链含偶氮基的聚硅氧烷类液晶高分子及其离聚物的合成与表征

以4－烯丙氧基－4’－硝基偶氮苯（M1）和4－烯丙氧基苯甲酸（M2）为单体，通过与聚硅氧烷接枝聚合，合成了一系列聚合物PI－PⅣ及离聚物PV－PⅧ。合成的液晶单体、聚合物及离聚物的结构均通过红外或核磁的验证，并通过DSC、偏光显微镜和X射线衍射研究了其液晶行为，聚合物PI－PⅣ及离聚物PV－PⅧ为向列型液晶。液晶基元的含量和离子 基元的引入对液晶的玻璃化温度（Tg）、液晶相范围（△T）等有显著的影响。聚合物PI-PⅣ随着液晶基元含量的增加，其Tg从98．8℃降低到61．9℃，相应地△T从19．8℃拓宽到43．6℃；离聚物PV－PⅧ的液晶行为随着离子含量的增加，其清亮点（Tc)从166．2℃降低于134.5℃，△T也相应地缩短，当离子含量达到40％时，离聚物的液晶相消失。     

含手性基元的侧链液晶聚合物的合成与性能表征

文中设计与合成了国内未见报道的单体M1、M2和系列手性液晶聚合物。通过差示扫描量热(DSC)、偏光显微分析(POM)、广角X射线衍射、旋光仪等测试手段研究了单体M1和手性液晶聚合物液晶性能。结果表明,M1为向列型液晶单体,M2为手性非液晶单体。聚合物P2~P4呈现近晶A相,P5,P6为胆甾相,P7的液晶性能已不明显,聚合物P8已没有液晶性能。具有宽的液晶相范围,液晶相范围均高于140℃。随着手性单体M2含量(0%~50%)的增加,聚合物的玻璃化转变温度、清亮点温度、液晶相范围均呈现降低趋势。     

新型希夫碱型缓蚀剂N-苯基邻羟基苯甲亚胺的合成及性能评价

以苯胺和水杨醛为原料,无水乙醇为溶剂,冰乙酸为催化剂,制备了一种希夫碱酸化缓蚀剂N-苯基邻羟基苯甲亚胺,研究了希夫碱缓蚀剂合成条件,最佳反应条件为：温度为90℃,最佳反应时间为4h,催化剂加入量为2ml,利用静态失重法评价缓蚀性能能达到98．5％以上。     

双缩合希夫碱耐温酸化缓蚀剂的合成及性能研究

为了解决原油开采中酸液腐蚀的问题,采用溶剂法合成出2种双缩合希夫碱缓蚀剂XFJ-1、XFJ-2.针对90℃、15％(质量分数)HCl的环境,通过静态失重法、极化曲线法等方法评价了其缓蚀性能,并采用模拟手段从分子层面解释了二者的缓蚀机理.结果表明:2种缓蚀剂在质量分数分别为1.0％时缓蚀效率分别可以达到82.90％和99...     

两种新型氢键诱导液晶材料的合成及表征

以对氨基苯甲酸、对硝基苯甲醛和吡啶衍生物为原料合成了两种新型氢键诱导液晶。用IR、1H-NMR和元素分析对所合成的化合物进行了结构表征,并用DSC和带热台的偏光显微镜分别对质子供体和超分子复合物复合前后的液晶行为进行了研究。结果表明:合成了目标化合物;IR结果证明了羧基和吡啶环间分子间氢键代替了羧基间的分子间氢键,复合物表现出分子的热力学行为;液晶行为研究证明了氢键复合物是典型的热致液晶且呈现明显的向列型液晶态,超分子液晶复合物较质子供体的液晶相范围宽且其相转变温度低于质子供体,说明分子间氢键起到了稳定液晶相态的作用。     

侧链胆甾液晶聚合物的合成及性能

合成了一种新型胆甾液晶单体(M1)和一种向列液晶单体(M2),通过与聚硅氧烷(PMHS)接枝共聚得到了系列侧链液晶聚合物P1~P6,通过傅立叶变换红外光谱(FT-IR)、差示扫描量热仪(DSC)、热失重分析(TGA)、偏光显微镜(POM)等手段对聚合物的结构、液晶性能及热性能进行了表征。随着胆甾液晶基元的减少,其玻璃化转变温度(Tg)、清亮点(Ti)逐渐降低。聚合物P1~P6均为胆甾型热致液晶,聚合物呈现出典型的胆甾液晶彩色Grand-jean织构、油丝及焦锥织构,并且颜色随温度升高发生变化。     

侧链液晶聚乙炔的合成及性能表征

取向液晶侧链引入聚乙炔主链促使主链共轭性提高,导致获得电活性和取向性的永久结合。最近,已有不少研究组将聚炔共轭聚合物作为刚性主链应用于制备侧链液晶聚合物。文中主要阐述带有液晶侧链聚乙炔的合成、液晶性及光学性能,并根据侧链液晶基元结构对其进行分类。     

侧链含有两种介晶基元的聚硅氧烷类液晶聚合物的制备与性能

合成了侧基带有两种介晶基元的聚硅氧烷类系列液晶聚合物（P1－P5），所用介晶单体M1为4－联苯二酚基－4’－（2－乙基已酰基）－4－烯丙氧基苯甲酸酯，M2为4－烯丙氧基苯甲酰氧基－4’－甲氧基苯，它们介晶区间分别为39℃和7．9℃。只含有单体M1的聚合物P1和只含有单体M2的聚合物P5的介晶区间分别为70．8℃和75．1℃；但是同时含有不同摩尔比的M1和M2的液晶聚合物P2－P4的介晶区间为240－250℃，比只含有一种介晶基元的P1或P5拓宽了约170℃，所有聚合物均低于室温就有液晶性能，且耐热性达310℃以上，属于非晶近晶织构。     

含侧甲基液晶双马来酰亚胺的合成及表征

通过甲基对苯二酚和对马来酰亚胺基苯甲酸,制得了一种低熔点的酯类液晶双马来酰亚胺.应用FT-IR、1H-NMR、DSC、HSPM对液晶双马来酰亚胺的结构和液晶行为进行了表征.结果表明,这类液晶双马来酰亚胺具有较低的熔点,侧甲基的存在使得液晶双马来酰亚胺的熔点下降了39℃.由HSPM观察到所合成的液晶单体具有向列型液晶所具有的典型的纹影织构,呈现出较好的热致液晶行为,并且液晶织构可以通过端基的交联聚合反应固定在交联网络中.     

Synthesis and properties of novel chiral side-chain liquid crystalline polysiloxanes containing different chiral pendant groups

Two novel chiral liquid crystalline monomers, and a series of their corresponding chiral side-chain polymers (P₁–P₇) based on poly(methylhydrogeno)siloxane have been prepared. The chemical structures and liquid crystalline properties of the synthesized monomers and polymers have been investigated using various experimental techniques. Thermal analysis shows that all polymers have wide mesophase temperature ranges with a high thermal stability. With the increase of M₂ molar ratio in the polymer systems, the isotropic phase transition and glass transition temperatures of all polymers increase, and the temperature ranges of N* phase and mesophase become broad. The effect of cholesteryl mesogens on mesophase behaviors, optical properties, and molecular arrangement of LC polysiloxanes and their advanced applications have also been discussed. For homopolymer P₁, it shows a single S_A phase. With increasing the content of M₂ in the polymer systems, P₂ and P₃ reveal a S_A–N* phase transition when they are heated, and P₄–P₇ reveal a N* phase. For N* phase polymers P₄–P₇, the reflection wavelengths exhibit blue shift, suggesting that the pitch decreases with a decrease in the amount of the smectic domains induced by the M₁. The reflection wavelengths of P₄–P₇ are almost across the entire visible region when they are heated, which offer stremendous potential for various optical applications. For P₂ and P₃, the reflection wavelengths show a very steep change around the temperature of the S_A–N* phase transition, which can be used as thermally sensitive liquid crystal devices requiring fast response, such as sensors, and thermally induced tuning.     

Synthesis and characterization of novel liquid crystalline polymers containing cholesteryl pendant groups

In order to investigate the chiral effect of cholesteryl pendant groups on the induction of the cholesteric phase, a new cholesteryl-containing liquid crystalline monomer was synthesized and copolymerized with an achiral comonomer in various molar ratios. The layer-like arrangement of the smectic mesophase with different monomeric compositions of copolymers was investigated using an X-ray diffraction analysis. The cholesteric liquid phase was induced by the chiral segments; the dependence of the reciprocal central reflection wavelength on the mole fraction of the chiral monomer for copolymers was investigated. This paper demonstrates the effect of chiral pendant groups on the induction of the cholesteric phase and layered molecular arrangement of side-chain liquid crystalline polymers.     

新型噻吩席夫碱中间体的合成及表征

在N2保护下,利用噻吩、N,N-二甲基甲酰胺、三氟氧磷制得产率、纯度较高的噻吩-2-甲醛.利用该中间体与4-氨基苯酚、对氨基苯甲酸合成了噻吩-2-甲醛缩4-氨基苯酚席夫碱、噻吩-2-甲醛缩对氨基苯甲酸席夫碱两种新型的含噻吩环席夫碱化合物,并通过红外、核磁对它们进行了结构表征.     

四-(对酰氧基苯基)卟啉的合成及液晶性能研究

合成了4个系列的中位－四（对酰氧基苯基）卟啉化合物，通过元素分析，紫外－可见光谱，红外光声光谱和核磁共振氢谱等分析手段表征了4种卟啉自由碱化合物，并肜DSC和偏光显微镜研究这些化合物的液晶行为，探讨了碳链长度对卟啉自由碱液晶性能的影响。     

Synthesis and characterization of photochromic star-like liquid crystal

A new photochromic star-like liquid crystal that is written by SiC₄ and containing four butoxyazobenzene mesogens in its periphery has been synthesized and characterized by the spectroscopic methods and thermal analysis. SiC₄ is nematic phase and its phase behavior is Cr138N147I145N118Cr. The quantum yield and photoisomerization of SiC₄ in chloroform (CHCl₃) and tetrahydrofuran (THF) have been studied by UV/Vis absorption spectra. The results indicate that the photochromism of SiC₄ in CHCl₃ and THF are in accordance with the first-order kinetics. The photochromism rate constants in CHCl₃ and THF are 10⁻¹ s⁻¹, they are 10⁷ times larger than those of side-chain liquid crystalline polymers containing the same azobenzene moieties. These results show that the star-like structure does not significantly affect the photoisomerization activity of the azobenzene mesogen in its periphery.     

Synthesis,structure, and mesomorphic properties of main-chain liquid-crystalline ionomers containing sulfonate groups

The mesogenic monomer M and a series of main-chain liquid crystalline ionomers (LCIs) containing sulfonate groups were synthesized. The LCIs were prepared by an interfacial condensation reaction of mesogenic monomer 1,4-phenylene-dicarbonic acid bis (4-carboxyl phenyl) ester, brittle yellow (BY), 1,10-sebacoyl dihydroxy, and 1,12-dodecanedioyl dihydroxy. The sulfonate groups introduced to the main-chain backbone were confirmed by ultraviolet spectroscopy. The mesomorphic properties were investigated by differential scanning calorimetry (DSC), thermo gravimetric (TG), and polarizing optical microscopy (POM). Experimental results demonstrated that the glass-transition temperatures increased slightly, melting temperature decreased, and the mesophase temperature ranges increased first and then decreased with increasing content of sulfonate group. All of the polymers were thermally stable up to 320 °C. The LCI _n s exhibited typical nematic schlieren textures.