含对甲氧基苯氧羰基偶氮苯基团的侧链液晶高分子的合成与表征

报道了新型的含对甲氧基苯氧羰基偶氮苯基团的甲基丙烯酸酯单体与含对甲氧基苯氧羰基苯基团的甲基丙烯酸酯单体的合成及其自由基共聚合．利用１Ｈ ＮＭＲ、ＩＲ、ＵＶ Ｖｉｓ、元素分析、ＧＰＣ、ＴＧ ＤＴＡ、ＰＯＭ及Ｘ 射线衍射等手段对偶氮单体及聚合物的结构与性能进行了表征,证明两种单体的共聚合产物为无规共聚物,而且各聚合物均具有较好的热稳定性．研究结果还表明,偶氮单体与聚合物在升温过程中均显示出向列相液晶织构,且聚合物的液晶相范围随偶氮含量的增加而变宽．     

含对硝基偶氮苯基团的侧链液晶高分子的合成及其光致变色性能研究

报道了新型的含对硝基偶氮苯基团的甲基丙烯酸酯单体与含介晶基团的甲基丙烯酸酯单体的合成及其自由基共聚合．利用１Ｈ ＮＭＲ、ＩＲ、ＵＶ Ｖｉｓ、ＧＰＣ、元素分析、ＤＴＡ及ＰＯＭ等手段对偶氮单体和聚合物进行了结构表征．证明两种单体的共聚合产物为无规共聚物，而且各聚合物在加热过程中均显示出明显的向列相液晶织构．研究了偶氮单体及其与介晶单体的共聚物的氯仿溶液和聚合物薄膜在紫外光诱导下的光异构化及热回复异构化行为．结果表明，它们在紫外光诱导下均能发生光致变色现象，而且介质对其光化学行为起决定作用．     

含对甲氧基苯氧羰基偶氮苯基团的侧链液晶高分子的光致变色 …

研究了含对甲氧基苯氧羰基偶氮苯基团的甲基丙烯酸酯单体及其与含对甲氧基苯氧羰基苯基团的甲基丙烯酸酯单体的共聚物的氯仿溶液,二甲基甲酰胺溶液和共聚物薄膜在紫外光诱导下的光导构化及热回复异构化行为。结果表明,它们在紫外光诱导下均能发生光致变色现象,且介质对其光致鸾以行为起决定作用。     

含对硝基偶所苯基团的侧链液晶高分子的合成及其光致变色性能研究

报道了新型的含对硝基偶氮苯基团的甲基丙烯酸酯单体与含介晶基团的甲基丙烯酸酯单体扔合成及其自由基共聚合，利用＾１Ｈ－ＮＭＲ，ＩＲ，ＵＶ－Ｖｉｓ，ＧＰＣ元素分析，ＤＴＡ及ＰＯＭ等手段对偶氮单体和聚合物进行了结构表征。证明两种单体的共聚合产物为无规共聚物，而且各聚合物在加热过程中均显示出明显的向列相液晶织构。     

含偶氮基团的侧链液晶高分子的研究进展

综述了含偶氮基团的侧链液晶高分子的制备方法及其在可逆光信息存储与非线性光学领域的应用。     

光致变色液晶高分子研究(Ⅳ)─含苯甲酸－4－甲氧基苯酯介晶基元和偶氮苯光色基元侧链共聚硅氧烷的液晶行为

用热台偏光显微镜和DSC法研究了含苯甲酸-4-甲氧基苯酯介晶基元和偶氮苯光色基元侧链共聚硅氧烷(PSⅡ)的液晶性。将非介晶基元并入液晶均聚物PSⅡ-1,共聚物PSⅡ-2、PSⅡ-3的液晶态类型不变,PSⅡ-4仅存在近晶相,PSⅡ-5～8无双折射现象,保持共聚物液晶性的最低含介晶基元单体的极限摩尔含量为80%.在液晶共聚物中,非介晶基组分含量增加时,其T_m、ΔH_m和ΔS_m降低;非介晶组分在10mol%时,T_i、ΔH_i和ΔS_i具有最小值。     

端基含36个己氧基偶氮苯基元的二代碳硅烷光致变色液晶树状高分子的光化学研究

研究了含36个己氧基偶氮苯介晶基元的二代(G2)光致变色液晶树枝状高分子在氯仿和四氢呋喃溶液中的最大吸收波长,摩尔消光系数,反顺光异构化反应速率常数,光化学回复异构化正逆反应速率常数及其平衡常数,G2和G1的光致变色反应速率常数kp为10-1s-1,而含偶氮基元光致变色液晶聚硅氧烷的kp为10-8s-1,因此液晶树状高分子的光响应速率比后者快107倍.     

含偶氮苯类星型液晶化合物的光致变色

The photochromism of a new star-like liquid crystal that was written by Si(AZO)4 centered by Si and containing four butoxyazobenzene mesogens in its periphery was described. The quantum yield, photoisomerization and photo back-isomerization of Si(AZO)4 in CHCl3 and THF are studied by UV/Vis absorption spectra. The results indicate that the photochromism and photo back-isomerization of Si(AZO)4 in CHCl3 and THF were in accordance with the first order kinetics. The photochromism and photo back-isomerization rate constants are 10-1 s-1, which are 107 times larger than that of side-chain liquid crystalline polymers containing the same azobenzene moieties. These results indicate that the star-like structure does not significantly affect the photoisomerization activity of the azobenzene mesogen in its periphery. The kt/kc of Si(AZO)4 is less than that of azobenzene mesogen which shows that the Si(AZO)4 has better photo-reversibility. So the star-like liquid crystal has potential applications and will become a new type photocontrolable switch and information functional material.     

含偶氮基团的聚丙烯酸酯型功能侧链液晶高分子的性能及其应用前景

综述了基于具光致双折射和光存储性质的偶氮功能基团的新型功能性侧链液晶聚丙烯酸酯的液晶性质、光电性质及应用前景.指出该类聚合物是一类非常重要的非线性光学材料 ,一般显示热致性向列型或近晶型液晶相, 液晶相转变温度和液晶态温度范围随链结构的不同发生显著变化,具有较短的电场及光场响应时间.此类材料在不断开发研究下可望用作长久的高对比度的光学信息储存材料.     

含偶氮基团的聚甲基丙烯酸酯型侧链液晶高分子的合成与表征

报道了一种新的含对甲氧基苯氨羰基偶氮苯基团的甲基丙烯酸酯单体及其自由基聚合产物的合成。利用元素分析,＾１Ｈ－ＮＭＲ、ＵＶ－Ｖｉｓ、ＧＰＣ、ＴＧ－ＤＴＡ、ＰＯＭ及Ｘ－射线衍射等手段对其结构与性能进行了表征。结果表明,偶氮单体不具有液晶性质,而聚合物则具有向列型液晶相存在,并且它在空气中具有很好的热稳定性。     

缩聚反应合成侧链液晶聚合物

侧链液晶聚合物的合成方法,可归纳为3类:一是烯基的单体,如甲基丙烯酸酯,或丙烯酸酯,氯代丙烯酸酯等,经自由基聚合反应,阴离子聚合反应及甲基丙烯酸酯的基团转移聚合反应,得到侧链液晶聚合物;二是变性反应,如聚硅氧烷与丙烯酸酯介     

偶氮苯型侧链液晶聚合物的阻隔特性研究

合成了偶氮苯侧链液晶聚合物聚甲基丙烯酸(3-[4-(4′-氰基偶氮苯)苯氧基]丙酯)(PM3ABCN),采用原位掠入射X射线衍射(GIXRD)方法研究了该聚合物膜在向列相和各向同性态(无定形相)时对气体的阻隔特性.并采用X射线能谱仪(EDS)分析铁片氧化后的氧含量,计算得到渗透通过聚合物膜的氧气的量.结果表明,当PM3ABCN膜处于各向同性态时,通过聚合物膜的氧气平均渗透量为1.92×10-3cm3 day-1m-2;而处于液晶态的膜对氧气的阻隔性提高了4.4倍,氧气平均渗透量为4.38×10-4 cm3day-1 m-2.结合样品表面的显微分析结果,探讨了液晶凝聚相结构对气体小分子的阻隔机理.     

MORPHOLOGICAL AND KINETIC STUDIES OF PHASE TRANSITIONS OF A SIDE-CHAIN LIQUID CRYSTALLINE POLYMER

The morphological changes of a side-chain liquid-crystalline polymethacrylate during isotropi-zation and liquid-crystallization transitions were studied by means of polarizing microscopy. These tran-sitions were found to be composed of the initiation of a new phase at local places of the old phase matrix andthe growth of the new phase domains. The kinetics of the liquid-crystallization of the polymer from anisotropic melt to a smectic mesophase was also investigated. The isothermal process of the transition can bedescribed by the Avrami equation. The values of the Avrami exponent were found to be around 2.6, which islower than the value usually obtained for crystallization transition of polymers, but larger than that reportedfor liquid-crystallization transition of main-chain polymers. These results may indicate the difference ingrowth geometry of new phase during transition between crystallization and liquid-crystallization in generaland between liquid-crystallization of main-chain and side-chain polymers. It was found that the liquid-crystallization of the used side-chain polymethacrylate may occur at small undercoolings with hightransformation rate similar to that of main-chain polymers and small-molecule liquid crystals, while thecrystallization of polymers can only proceed at large undercoolings. These phenomena can be explained bythe idea that the surface free energy of nucleus during liquid-crystallization transition is less than that forcrystallization, and evidence was obtained from analysis of the temperature dependence of the transformationrate.     

MORPHOLOGICAL STUDIES OF A THERMOTROPIC SIDE-CHAIN LIQUID CRYSTALLINE POLYMER DURING MESOPHASE TRANSITIONS*

The morphological features of a side-chain liquid crystalline polymer during the mesophasetransitions were investigated by using the DSC technique. The polymer used was polyacrylate with mesogensof three benzene rings attached to the main chain through a flexible spacer. A special two-phase texture wasobserved in the transition temperature range. Similar to main-chain liquid crystalline polymers the transitionprocess of the side-chain liquid crystalline polymer was composed of an initiation of the new phase at localplaces of the old phase matrix and a growth process of the new phase domains.     

SYNTHESIS AND CHARACTERIZATION OF TRIAZOLE CONTAINING LIQUID CRYSTALLINE POLYMERS THROUGH 1,3-DIPOLAR CYCLOADDITION POLYMERIZATION

Liquid crystalline polymers containing 1,2,3-triazole units as linking groups have been synthesized from the monomers containing triad ester diazide and flexible dialkyne ester by 1,3-cycloaddition reaction and were characterized. Click reaction of azide and alkyne functionals catalyzed by Cu(I) yielded target polyesters with 1,2,3-triazole groups.The structure of the polymer was confirmed by spectral techniques.GPC analysis reveals that the polymers have moderate molecular weight with narrow distributio...     

含偶氮苯基侧基聚硅氧烷的合成及光致变色性

含偶氮苯基侧基聚硅氧烷的合成及光致变色性张其震，张静智，王艳（山东大学化学系济南２５０１００）（山东大学环境科学中心济南２５０１００）关键词聚硅氧烷，光致变色，光异构化，量子产率将光致变色性和液晶性化合物结合可得到新的多功能高分子材料，Ｒｉｎｇｅｄｏ...