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1.
综述了近十多年来以环三膦腈为核的非线性聚膦腈高分子的合成、性能及其应用。重点介绍了直接亲核取代法与多官能团引发剂法在合成以环三膦腈为核的星形高分子中的应用,以及发散法与收敛法在合成以环三膦腈为核的树形高分子中的应用。简要阐述了以环三膦腈为核的星形、树形高分子在光电材料、生物医用材料等方面的应用,并展望了以环三膦腈为核的非线性聚膦腈高分子的发展趋势和方向。  相似文献   

2.
分别以胆固醇、胆酸为原料,合成了5种甾核基酯类化合物,采用红外光谱(FTIR)和紫外光谱(UV)对其结构进行表征,并用偏光显微镜(POM)和示差扫描量热法(DSC)研究其液晶行为。结果表明,合成的小分子产物丙酸胆固醇酯、苯甲酸胆固醇酯具有一定的液晶性能,而乳酸胆固醇酯和高分子的聚乳酸胆固醇酯、聚乳酸-胆酸共聚物在熔融状态下不具有液晶性质。  相似文献   

3.
报道了一种制备具有“核-壳”结构和双重释放过程的可降解抗炎缓释系统(3)的新方法。以聚(乙交酯-丙交酯)(PLGA50)为药物载体,先通过热熔挤出法将绿原酸(CA)与PLGA50共挤出得挤出物(1);利用静电纺丝法在1表面包裹一层“PLGA50+CA”静电纺丝膜(2),制得具备“核-壳”结构的材料(3)。采用SEM, TGA, DSC和LC-MS研究了CA的热稳定性,1的热力学性能,3的微观形态和体外药物释放行为。结果表明:3具有“核-壳”结构;引入CA,降低了PLGA50的玻璃化转变温度;3的药物释放为双重释放过程。  相似文献   

4.
“酚醛树脂的合成”是一个典型的高分子化学逐步聚合实验,教材中原有的实验方案与石油工程专业结合不紧密,导致学生对酚醛树脂的合成机理、油田应用了解不够深入。通过对原有实验方案的不足之处进行了分析,提出用氢氧化钠溶液替代氨水作为反应的碱性催化剂,所合成的酚醛树脂具有良好的水溶性。随后将所制备的水溶性酚醛树脂用作聚丙烯酰胺的高温交联剂,得到油田常用的调剖堵水化学凝胶。改进后的实验方案更加贴近石油工程专业的现场应用,操作更为便利安全,同时满足了“高分子化学及物理”“油田化学”2门课程对该知识点学习的要求,使学生在加深高分子化学基础的同时还增强了应用所学知识解决工程问题的能力。  相似文献   

5.
夏静静  张克华  鞠俊 《有机化学》2009,29(11):1849-1852
将醛、乙酰乙酸乙酯和醋酸铵的多组分反应引入到水相回流条件下, 合成了一系列具有生物和药物活性的1,4-二氢吡啶化合物. 在此基础之上, 向反应体系中直接加入氧化剂MnO2, “一锅法”生成了芳构化的吡啶衍生物, 将原来Hantzsch酯的合成与芳构化在“一锅”里实现, 缩减了反应步骤, 提高了反应效率.  相似文献   

6.
ZSM-5沸石分子筛合成的研究   总被引:2,自引:0,他引:2  
ZSM-5沸石分子筛是70年代初由美国Mobil公司最早开发的。由于它对烷基化、异构化、歧化、选择裂化和甲醇合成汽油等反应具有独特的催化性能,是目前被广泛重视的一种新型催化剂材料。自从它问世以来,很长一段时间内,认为有机胺是合成ZSM-5沸石分子筛的必不可少的原料。1977年Whittan等发表了用异丙醇等醇类合成ZSM-5分子筛之后,我们成功地用“乙醇、氨、导向剂法”,“乙醇法”和“只加导向剂法”合成了ZSM-5分子筛。  相似文献   

7.
张勇杰  李化毅  曲敏杰  冯钠  杨威  张翀 《化学进展》2016,28(11):1634-1647
实现聚烯烃功能化是制备高性能聚烯烃材料、拓展聚烯烃应用的重要手段,几十年来得到了学术界及工业界的广泛关注。聚烯烃接枝共聚物作为一类重要的功能化聚烯烃,包含聚烯烃链段(PE、PP等)及功能化聚合物链段(PS、PMMA、PEG等),因而在提高功能单元含量的同时能保持聚烯烃单元优异的结晶、加工性能。结构明确的聚烯烃接枝共聚物,具有结构参数可控、综合性能可调的特点,对于认识聚合物材料结构-性能关系、拓展聚烯烃应用范围具有重要的学术和实际意义。聚烯烃接枝共聚物的合成方法可以分为三种类型:“共聚接枝(graft-through)”、“引出接枝(graft-from)”、“偶联接枝(graft-onto)”。前两种合成方法往往涉及烯烃配位聚合与其他聚合方式的机理转化过程;其中,反应性聚合物中间体作为大分子引发剂、大分子RAFT试剂、大分子单体参与接枝反应,实现接枝共聚物的可控制备。第三种方法思路简单明确,即利用聚烯烃侧基反应性基团与其他聚合物反应性端基之间的高效偶联反应实现接枝共聚物制备。本文从合成、结构及性能三方面较为全面地综述了结构明确聚烯烃接枝共聚物的研究进展,着重讨论了新兴合成方法及相应接枝共聚物的潜在应用。  相似文献   

8.
颜静  顾军渭  耿旺昌  闫毅 《化学教育》2021,42(4):107-113
从高分子学科确立到现在已经经历了整整一个世纪。围绕高分子领域的历次诺贝尔奖,重点回顾了“高分子”概念的确立、高分子合成化学、高分子理论、功能高分子等领域的里程碑事件,分析了高分子学科的未来发展趋势。  相似文献   

9.
姚臻  戴博恩  于云飞  曹堃 《化学进展》2016,28(7):1062-1069
巯基-环氧反应作为一类典型的“点击化学”具有反应速度快、选择性高且反应条件温和等优点,近年来备受关注。本文首先阐述了巯基-环氧反应的碱催化机理,并评述了碱性催化剂、取代基团以及溶剂等因素对于巯基-环氧反应速率的影响。归纳认为,无机碱如氢氧化锂以及有机碱如四丁基氟化铵具有较高催化活性,并比较了无机碱和有机碱催化剂的优缺点;与供电子基团连接的巯基化合物以及与吸电子基团连接的环氧化合物具有较高的反应活性,位阻效应也对其有影响;在无溶剂的本体条件下反应活性较高。同时,重点介绍了巯基-环氧反应在高分子材料领域中应用的最新进展,并将其分为在溶剂中合成结构可控的高分子(包括线型或复杂结构高分子的合成和高分子或表面的修饰改性)以及本体条件下制备性能优良且具有应用价值的高分子网络两大类进行讨论。最后,简要展望了其发展前景。  相似文献   

10.
张弛 《化学教育》2013,34(1):42-44,81
指导高一学生利用金属探测仪开展化学研究性学习活动;带领学生一起构思立足于化学、指向实践和应用的研究体系,主要对金属探测仪从功能(即“能”与“不能”的问题)和性能(即灵敏度的“好”与“差”问题)2个方面加以实验研究。为进一步丰富和完善研究,再对金属的带电状态、电磁辐射的存在状态加以探测对比分析,而后对原理加以分析,形成了基本结论,提出了实践操作的建议,并对整个活动加以总结和反思。  相似文献   

11.
Eight amino acids (ethanolamine, glycine, alanine, β-aminobutyric acid, leucine, methionine, histidine and asparagine) were identified and quantified in Spanish wines by high performance liquid magneto-chromatography (HPLMC) with UV-V spectrophotometry. For this method, the amino acids are first complexed with mono(1,10-phenanthroline)-Cu(II) to confer them paramagnetic properties, and then separated by application of a low magnetic field intensity (5.5 mT) to the stationary phase contained in the chromatographic column. Principal components analysis of the results obtained grouped together the wine samples according to their denomination of origin: “Ribera del Duero”, “Rueda” or “Rioja” (Spain). Through cluster analysis, a series of correlations was also observed among certain amino acids, and between these groupings and the type of wine. These clusters were found to reflect the role played by the amino acids as primary or secondary nutrients for the bacteria involved in alcoholic and malolactic fermentation.  相似文献   

12.
“Masked” areneboronic acids have been prepared by Ir-catalyzed C-H borylation of arenes. A [Ir(OMe)(cod)]2 complex with a DPPE ligand showed the highest catalytic activity in the C-H borylation of benzene at 80 °C. The reaction system can be applied to substituted arenes, including halogen-substituted arenes. 1,3-Dihalobenzenes undergo the C-H borylation at their 5-positions in a regioselective fashion, affording 3,5-dihaloareneboronic acid derivatives, which serve as useful coupling modules for the convergent dendrimer synthesis.  相似文献   

13.
The photostability of eight blue-emitting derivatives of 2-aminoterephthalic acid, three of them containing a stabilizer residue in their molecule in dimethylformamide was investigated. Copolymerisation of methyl methacrylate with four of them, monomer compounds and whitening of methyl methacrylate “in mass” with one of the compounds was accomplished. The copolymers obtained have an intense stable to solvents fluorescence. Photostability of the compounds, thus included in the polymer chain increased. The influence of the luminophores on the photostability of the inherently and whitened “in mass” polymers was established.  相似文献   

14.
制备出2种含有单羟基的二苯甲酮类化合物: 4-[(2-羟乙基)(甲基)氨苯基]苯甲酮(NBP)与(4-氯苯基)[4-(2-羟乙基)(甲基)氨基]苯甲酮(NBP-Cl), 以此为引发剂引发D,L-丙交酯聚合制备不同分子量的聚乳酸(PLA), 并对其进行结构表征和性能测试. 光学测试结果表明, 在室温条件下, NBP和NBP-Cl仅具有荧光发射性能, 而PLA表现出荧光和室温磷光双重发光性能; 重原子效应导致聚合物室温磷光增强, 但磷光寿命减少; 随着PLA分子量的减小, 聚合物磷光寿命先增加后减少. PLA的热重分析数据显示其具有优异的热学性能, 大大拓宽了该双重发光材料的应用范围.  相似文献   

15.
The anionic methods for the synthesis of homo- and heteroarm (hybrid) star-shaped polymers using fullerene C60 aPre considered. The possibilities of fullerene C60 as an agent of combination of living polymer chains and the procedures of transformation of polymer derivatives of C60 (hexaadducts) into polyfunctional macroinitiators of anionic polymerization of vinyl monomers are shown. The methods for functionalization of polymer fullerene derivatives and their combinations into structures of complex controlled architecture are presented. The structural features and initiating properties of the living polymer fullerene derivatives and their role in the formation of heteroarm star-shaped macromolecules with the controlled number of branches and predetermined molecular weight characteristics of the arms are discussed. The hydrodynamic properties of the star-shaped fullerene-containing polymers are considered. The data on the small-angle neutron scattering study of self-organization of the stars in solutions are presented.  相似文献   

16.
Two cyclodextrin-based chiral stationary phases have been prepared by immobilization of functionalized mono-6-azido-β-CD derivatives to alkynyl modified silica via “click” chemistry and applied to the HPLC enantioseparation of various chiral compounds. The perphenylcarbamated CD CSP (CCP-CSP) exhibited excellent chiral recognition of a wide range of analytes including racemic aryl alcohols, flavonoids, bendroflumethiazide, atropine and some β-blockers. Methanol proved to be a better organic modifier than acetonitrile for most of the analytes with the exception of bendroflumethiazide. The “click” chemistry immobilized permethylated CD CSP (CCM-CSP) afforded poor chiral recognition for most analytes, but could resolve non-aromatic ionone derivatives which were not separated on CCP-CSP. These results suggest that resolution with cyclodextrin derived CSPs depend on a complex interplay of ‘host’–‘guest’ inclusion, hydrogen bonding, π–π and hydrophobic interactions.  相似文献   

17.
Si-Chun Yuan  Bin Du  Jian Pei 《Tetrahedron》2009,65(21):4165-6967
A series of monodisperse, well-defined, star-shaped truxene derivatives bearing oligo(fluorene ethynylene) (OFE) branches were constructed through a convergent synthetic strategy. The radius of the largest molecule TOFE4 was up to about 4.5 nm. Linear OFE branches with different length were first constructed in high yields alternately using the Sonogashira cross-coupling and propargyl alcohol deprotection reaction. The detailed investigation of their photophysical properties in solution and in film indicated that these star-shaped molecules exhibited obvious size effects on their distinct photoluminescence and electroluminescence behaviors. Furthermore, good performances were achieved from the fabrication of double-layer organic light-emitting diodes using these star-shaped molecules as active materials.  相似文献   

18.
We review in this report the preparation of several side-chain fluorinated analogues of biologically important imidazoles and indoles. The building blocks used should also have applications in other synthetic problems. The addition of “FBr” to vinyl imidazole derivatives was used to prepare β-fluoro- and β,β-difluorohistamine and histidinols, as well as β-fluorourocanic acid. Deoxyfluorination of intermediate acylindoles was used to prepare a series of β,β-difluorotryptamine derivative, including the fluorinated analogue of the important neurotransmitter, serotonin.  相似文献   

19.
Two series of new high fluorescent polymeric materials based on copoly(styrene-maleic anhydride) (SMA) were prepared by the condensation of SMA with fluorescent groups. One series consists of 1,8-naphthalimides derivatives that are linked with SMA. The other series were prepared by the condensation of SMA with 3,4,9,10-perylene tetracarboxylic mono-anhydride mono-imide. These simple routes to copolymer of styrene and maleic anhydride containing pendent luminescent moiety are promising in increasing fluorescent quantum yield in solid state and processing, in which styrene is employed as “diluents”. The luminescent and the preliminary photovoltaic properties of these copolymers have been investigated.  相似文献   

20.
This review covers our extensive research activities in the area of fluorine containing phospha- and arsaalkenes as well as selenocarbonyls, which differ considerably in their properties and reactivities from their alkyl and aryl counterparts and thus contribute in a gratifying manner to the still growing field of unsaturated element-carbon compounds of 3rd and 4th row main group elements E. Of particular interest is the influence of the fluorine substituents and other small groups (OR, NR2) with either inductive and/or mesomeric effects on the polarity and reactivity of the EC bond. Addition reactions of proton acidic and hydridic polar HX reactants as well as [2+2], [3+2] and [4+2] cycloadditions have been thoroughly studied. The results obtained allow a classification of the EC systems within five different types, A to E, and prove a change from “normal” to “inverse” heteroalkenes in this sequence. The ligand properties of some derivatives have also been investigated in some detail.  相似文献   

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