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1.
Linear polysiloxanes with pendant benzo-15-crown-5 moieties have been synthesized from 3′-or 4′-allylbenzo-15-C-5 via hydrosilylation of methyldichlorosilane,followed by polycondensation with silanol-terminated polydimethylsiloxane.It was found that the polysiloxanes could be used as carriers in bulk liquid membrane to transport ions.Factors influencing transport rate have been investigated.  相似文献   

2.
A modified method of preparing crown functionalized linear polysiloxane has beendescribed. 4'-Allyldibenzo-18-crown-6 was subjected to hydrosilylation withmethyldichlorosilane, followed by polycondensation with silanol-terminatedpolydimethylsiloxane to give the title crown functionalized linear polysiloxane. Thetransport properties of sodium, potassium, and ammonium salt through a bulk liquidmembrane system using the new type of crown functionalized linear polysiloxane as acarrier were investigated. It is worthy to point out that the carrier can be used repeatedlyat least six runs with no apparent change in the transport rate of potassium ion.  相似文献   

3.
A new type of palladium chelate of β-diketone-based side chain liquid crystal polysiloxane (Pd-DKLCP) has been synthesized by chelation reaction of palladium dichloride with polymeric ligand, β-diketone polysiloxane (DKLCP), using THF as solvent at R.T.. The Pd-chelation results in greatly increasing the phase transition temperature T_K and the enthalpy change △H_K from crystal to liquid crystal state and making the temperature range of LC state △T(△T=T_(Cl)-T_K) widened. All these chelates Pd-DKLCP's do not show T_(Cl) until decomposition at 205℃. It is noteworthy that the Pd-chelation can exert more positive effect on the mesomorphic behaviour of the polymer ligand than the counterpart Cu-DKLCP does. It is probable due to the bigger size of disc-like mesogen formed from β-diketone and Pd~(+2) ion with 4d orbital.  相似文献   

4.
The electrochemical polymerization of catechol on platinum has been carried out using repeated potential cyclingbetween-0.2 and 1.1 V (versus SCE). The electrolytic solution consisted of 0.2 mol dm~(-3) catechol, 0.5 mol dm~(-3) NaCl and0.1 mol dm~(-3) Na_2HPO_4 with pH 8.72. Catechol can not be polymerized at pH≥10.12. Polycatechol has an electrochemicalactivity at pH≤4. The anodic and cathodic peak potentials of polycatechol shift towards more negative values as the pH ofthe solution increases from 1 to 4. The electrochemical activity of polycatechol hardly changes in this pH region, but itdecreases slowly with time. This is caused by oxygen in air, which leads to an irreversible oxidation of polycatechol. Thisproperty is favorable for protecting metals from corrosion. Raman and FTIR spectra of polycatechol and catechol are quitedifferent. AFM images of polycatechol films provide evidence that the image of the oxidized state of polycatechol ismarkedly different from that of the reduced one. This difference is caused by doping and dedoping of polycatechol.  相似文献   

5.
Theuseofzeolitemembranesinseparationorcombinedreactionandseparationprocesesisveryatractive.Advantagesofusingsuchatypeofmembra...  相似文献   

6.
SYNTHESISANDSELF-ORGANIZATIONPROPERTIESOFANOVELBILAYERMEMBRANECONTAININGANTHRAQUINONE¥CHunJingLIU;GuoWenLI;YongChi,TIAN(KeyLa...  相似文献   

7.
A new type of metal coordinated liquid crystalline polymers has been synthesized by complexation of metal ions with β-diketone based side chain liquid crystal polysiloxane (DKLCP). The complexation of copper ions with DKLCP greatly increases the phase transition temperature T_k from crystalline state to liquid crystalline state and T_(cl) from LC to isotropic state and makes the range of phase transition ΔT (ΔT=T_(cl)-T_k) widened. These complexes are soluble in common organic solvents. However, the incorporation of europium ions into DKLCP molecules gives rise to reduction in liquid crystallinity and crosslinking in some cases. The DKLCP coordinated with suitable amount of Eu ions can show good liquid crystallinity and fluorescent property.  相似文献   

8.
IntroductionTheuseoflarge-PorezeolitessuchasXandYforcarelyzingtheesterificationhasbeenearlysuggestedbyBergklllandnorelationshipbetweentheactivityandsubdueaciditywasobserved.ItalianPatent[2]reportedthatdecationizedYzeolitesareveryactiveandselectivecatalyst…  相似文献   

9.
SYNTHESIS AND COMPLEXATION PROPERTIES OF NEW DIOXO TETRAAMINE LIGANDS WITH 8-METHYL QUINOLINE AS FUNCTIONAL PENDANT(S)SYNTHES...  相似文献   

10.
A side chain liquid crystalline copolysiloxane, which would show electro-optic effects as known from low mass liquid crystal, was synthesized by hydrosilylation reaction, and the two homologous monomers with different length spacers containing Schiff's base mesogen with—NO_2 terminated group were grafted toa polysiloxane main chain. Residual monomer in crude product is effective in reinforcing the response to an electric field over that of pure polymeric liquid crystal.  相似文献   

11.
胆甾侧链聚硅氧烷高分子液晶的合成与相行为研究   总被引:2,自引:1,他引:2  
本工作利用双键与Si-H键的加成反应合成了以丙烯酸胆甾醇酯为侧链的硅氧烷梳状聚合物液晶ECS.聚合物的结构得到了核磁与红外分析的证明.偏光显微镜和DSC对ECS的相态转变研究表明,ECS在一定的温度范围内能够形成液晶相,液晶相的存在范围与聚合物的结构密切相关.  相似文献   

12.
通过硅氢加成法合成了侧链为长链烷基醚的聚硅氧烷及共聚物,研究了其相转变性质以及由其组成的共混硅橡胶薄膜对避孕药物(左旋十八甲基炔诺酮)的释放性能.结果表明:聚硅氧烷的熔融温度随侧链烷基的增长而提高;共聚硅氧烷的熔融温度随较长烷基的比例增加而提高;聚硅氧烷的侧链烷基呈侧向有序性排列.药物分子透过薄膜的速率及其温度依赖性与共混膜中侧链烷基的有序状态有关,即由晶态转变为非晶态时,药物的透过速率加快  相似文献   

13.
偶氮苯侧链共聚硅氧烷的合成及液晶行为的研究   总被引:7,自引:0,他引:7  
以苯酚、十一烯酸、正溴己烷、对硝基苯酚和二氯亚砜为主要原料 ,通过取代、还原、重氮化和偶合等反应 ,合成了一种新的液晶单体 4 己氧基 4′ 十一烯 [1 0 ] 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高分子液晶 .通过1 H 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  相似文献   

14.
A variety of mesomorphic side-chain polysiloxanes were synthesized by using hydrosilylation reaction withdicyclopentadienylplatinum (Ⅱ) (DPPC) as the catalyst. The mesogenic groups are derivatives of stilbene with cyano or nitrotail groups. The products were characterized by DSC, X-ray deffraction and polarizing optical microscopy (POM). All thepolymers were found to have relatively low T_g and can form a smectic liquid crystal phase.  相似文献   

15.
主链型液晶聚硅氧烷聚氨酯的合成及性质   总被引:12,自引:0,他引:12  
合成了主链型联苯类及氧化偶氯苯类液晶聚硅氧烷聚氨酯弹性体,采用红外光谱,示差扫描量热,动态粘弹谱及带热台偏光显微镜等方法对聚合物进行了表征,讨论了它们的结构与性能.研究结果表明,这一系列多嵌段聚氨酯多数是向列型的液晶高分子聚合物,液晶相的形成同嵌段聚氨酯样品的软硬段相互作用有着密切的联系  相似文献   

16.
水合氯化锰和冠醚B15C5可在丙酮和无水乙醇中生成一种淡粉红色固态配合物:3MnCl_2·2815C5·4H_2O。本文通过元素分析、紫外分光光度分析、气相色谱、紫外光谱、X-射线衍射、差热与热重分析等研究了配合物的组成和性质,测定了它在一些有机溶剂中的溶解度。  相似文献   

17.
以 4 ,4′ (α ,ω 烷亚甲基二酰氧 )二苯甲醛和二氨基二苯并 14 冠 4为单体 ,采用溶液缩聚方法 ,首次合成了一类新的含冠醚环的席夫碱型液晶高分子 .一种单体采用脂族二酰氯和对羟基苯甲醛反应制备 ,另一种新的单体采用二硝基二苯并 14 冠 4 ,在钯 碳催化剂存在下 ,水合肼还原制备 .通过1H NMR、13 C NMR和分子力学计算方法研究了二氨基二苯并 14 冠 4的两种异构体的空间立体结构 ,发现能从1H NMR谱图上区分它们的立体结构 .它们的立体结构近似属于Cs 和C2 群 .聚合物的分子量不高 ,Mn 在 130 0 0~ 2 4 0 0 0之间 .单体的结构通过元素分析、IR、1H NMR和MS等方法确证 .聚合物的性质采用GPC、DSC、TG和POM等方法进行了研究 .发现所有的聚合物加热到各自的熔融温度 (Tm)以上都能形成液晶态 ,在液晶态可以观察到向列相的丝状织构和纹影织构 .聚合物的玻璃化转变温度 (Tg)、熔融温度和各向同性温度 (Ti)随聚合物分子中柔性间隔基的变化而变化 ,它们有较高的清亮点温度和宽的液晶态温度范围 .WAXD的研究进一步证实了聚合物的液晶性  相似文献   

18.
A novel series of liquid crystalline copolyesters with T-shaped two-dimensional mesogenic unit and crown ether cycle of cis-4,4′-bis(4-hydroxyphenylazo)dibenzo-18-crown-6 was prepared via solution condensation polymerization from 4,4′-(α,ω-hexanedioyloxy)dibenzoyl dichloride(M_1),2-(4′-ethoxyphenyl)hydroquinone(M_2)and cis-4,4′-bis(4- hydroxyphenylazo)dibenzo-18-crown-6(M_3).The molecular weights of copolyesters are not high,and the intrinsic viscosity [η]of copolyesters ranges from 0.29-0.43.The monomer...  相似文献   

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