用丙烯酸类手性配位体交换树脂拆分DL-氨基酸的研究

本文利用以铜络合的手性L-脯氨酸聚丙烯酸类交换树脂为柱色谱的固定相,对DL-苯丙氨酸、DL-苯丝氯酸、DL-酪氨酸、DL-色氨酸、DL-组氨酸等芳香氨基酸的拆分进行了研究。实验结果表明,除了组氨酸之外,其它氨基酸均能完全拆开,且D型先于L型流出柱子。通过测定L-Pro-PGMA-Cu(Ⅱ)的红外光谱,提出了它在配位体交换过程中的配位结构模型。     

Separation of Neutral Amino Acids with Ligand Exchange Resins

Four neutral amino acids (Gly, Ala,.Val and Leu) were separated with ligand exchange resins. The separation capacity of the ligand exchange resins is compared with that of common ion exchange resins. The effects of eluent, column temperature, and central metal ions of the support on the separation are studied. The relationship between matrix structure of resins and their separation capacity is analysed.     

配位体交换树脂对中性氨基酸分离性能的研究

采用配位体交换树脂对中性氨基酸(Gly,Ala,Val和Leu)进行了分离,并与一般阳离子交换树脂的分离性能进行了比较,对淋洗剂、柱温等分离条件进行了实验;研究了树脂载体结构、功能基及配位中心离子对分离性能的影响。     

用低交换容量聚苯乙烯型强酸性阳离子交换树脂柱色谱分离中性氨基酸

通过磺化苯乙烯 -二乙烯苯共聚物或商品化的聚苯乙烯型强酸性阳离子交换树脂 ( 0 0 1× 7)的逆磺化反应 ,得到一系列不同交换容量的聚苯乙烯型强酸性阳离子交换树脂 .研究了丙氨酸和缬氨酸及缬氨酸和亮氨酸在这些树脂柱上的色谱分离 .结果表明 ,用两种方法得到的树脂对丙氨酸和缬氨酸的色谱分离性能基本相同 ;同时中性氨基酸与聚苯乙烯型强酸性阳离子交换树脂之间的作用包括离子作用和疏水作用 ,且二者之间存在协同作用 .树脂的交换容量较低时对中性氨基酸有更好的分离性能     

Thermal Characterization of Polyurethane Acrylate Resins

Polyurethane acrylate resins cured by two different ways, a thermal way and a photochemical way, are investigated by means of differential scanning calorimetry (DSC) and thermally stimulated depolarization currents (TSDC). Even if both curing methods lead to the same material from a chemical point of view, we show that important differences exist between the thermocured resin and the photocured resin in terms of molecular relaxation behaviour.This revised version was published online in November 2005 with corrections to the Cover Date.     

离子交换树脂

简要介绍了离子交换树脂的概念、发展简史、组成、分类、作用原理、合成路线及性能。用表格简列出应用的各个方面,并说明了应用的优、缺点,最后扼要地指出了发展的方向。     

Chiral Polymers and Optical Resolution: Investigation of the Mechanism of Ligand Exchange for Resolution of DL-Amino Acids

Abstract

Using novel class chiral ligand polymers which have different chemical environment in chiral cavity, we investigated their functional properties of chiral recognition for DL-amino acids and discussed ligand exchange chromatography of DL-amino acids on different chromatographic conditions in detail.     

碱性树脂吸附有机羧酸的溶胀现象

选用强碱性树脂（201×4）,弱碱性树脂（D301G）为吸附剂,以乳酸和乙酸稀溶液为吸附分离对象,实验测定了碱性树脂对有机酸和水的组分吸附量,讨论了树脂的溶胀现象．结果表明,随吸附温度的上升,碱性树脂的溶胀程度增大;随着树脂上酸的吸附量的增大,水的组分吸附量也增大．通过对水的组分吸附量的分析,提出溶胀中存在吸水量和表面增益量两个方面的影响．以水的表面增益量为基础,讨论了强碱性树脂201×4和弱碱性树脂D301G对酸－水体系的选择分离性能．     

α-羟基酸在不同的手性配体交换色谱固定相上分离性能的考察

合成了L-羟基脯氨酸，L-脯氨酸，L-苯丙氨酸3种硅胶链合手性配体交换色谱固定相，并用于α-羟基酸的直接光学分离，取得了较为满意的结果。对不同的手性配体交换色谱固定相的分离性能进行了比较，并详细考察了流动相pH值、金属离子浓度、柱温等因素对分离效果的影响，从而进一步优化了色谱分离条件。     

Comparative Study of Chromium(VI) Removal from Simulated Industrial Wastewater with Ion Exchange Resins

Russian Journal of Physical Chemistry A - Ion exchange process is an alternative technique for removal of heavy metal ions from industrial wastewater. The main aim of this paper is to evaluate the...     

Spectroscopic Investigations of Phase-Separated Thermotropic Layers Based on UV Cured Acrylate Resins

Summary: In this paper spectroscopic techniques were adapted and applied to characterize the optical and morphological properties of thermotropic resins. Thermotropic films were prepared by variation of resin base and thermotropic additives. By UV/Vis/NIR spectroscopy the solar optical properties, the switching temperature, the switching process and the residual transmittance in the opaque state were determined. To control the sample temperature from ambient to 100 °C a conventional UV/Vis/NIR spectrophotometer equipped with an Ulbricht-sphere was adapted by a heating stage. Additive content, distribution and scattering domain size were characterized by Differential Scanning Calorimetry, Attenuated Total Reflectance spectroscopy and microscopic techniques. For the investigated film types hemispheric solar transmittance values ranging from 80 to 87% and 75 to 85% were obtained in the clear and the scattering state, respectively. The diffuse solar transmittance values increased significantly from 14 to 40% below the switching temperature to 36 to 70% at elevated temperatures. The thermotropic resins exhibit a steep and rapid switching process with switching temperatures between 45 and 70 °C. The materials with the best switching properties are characterized by distinct differences in refractive index between the components, a uniform additive distribution and scattering domains with diameters below 1000 nm.     

阴离子交换树脂催化丙烯腈与二醇的Michael加成反应

利用阴离子交换树脂为催化剂进行了丙烯腈与二醇的Ｍｉｃｈａｅｌ加成反应的研究，对影响反应的诸因素进行了讨论，产物收率为７０－９０％。     

Resolution of the Optical Isomers of Underivatisized Amino Acids on Chemically Bonded Chiral Phases by Ligand Exchange Chromatography

Abstract

A method for the direct separation of racemates by HPLC is described. A chiral stationary phase is synthesized, suitable for ligand exchange chromatography. L-proline is chemically bonded to silica gel via 3-glycidoxypropyltrimethoxysilane. The bonded support is loaded with Cu(II) ions as a complexing agent. Complete resolution of amino acid racemates can be obtained in less than ten minutes. α-values up to 3.5 are observed.     

Resolution of Halogenated Mandelic Acids through Enantiospecific Co-Crystallization with Levetiracetam

The resolution of halogenated mandelic acids using levetiracetam (LEV) as a resolving agent via forming enantiospecific co-crystal was presented. Five halogenated mandelic acids, 2-chloromandelic acid (2-ClMA), 3-chloromandelic acid (3-ClMA), 4-chloromandelic acid (4-ClMA), 4-bromomandelic acid (4-BrMA), and 4-fluoromandelic acid (4-FMA), were selected as racemic compounds. The effects of the equilibrium time, molar ratio of the resolving agent to racemate, amount of solvent, and crystallization temperature on resolution performance were investigated. Under the optimal conditions, the resolution efficiency reached up to 94% and the enantiomeric excess (%e.e.) of (R)-3-chloromandelic acid was 63%e.e. All five halogenated mandelic acids of interest in this study can be successfully separated by LEV via forming enantiospecific co-crystal, but the resolution performance is significantly different. The results showed that LEV selectively co-crystallized with S enantiomers of 2-ClMA, 3-ClMA, 4-ClMA, and 4-BrMA, while it co-crystallized with R enantiomers of 4-FMA. This indicates that the position and type of substituents of racemic compounds not only affect the co-crystal configuration, but also greatly affect the efficiency of co-crystal resolution.     

离子交换树脂在分析化学中的应用

简要评述了离子交换树脂在分析化学中的应用。包括离子交换树脂预富集技术从稀溶液中浓缩痕量离子,离子交换树脂相分光光度法测定微量离子,离子色谱在无机分析中的应用,以及离子交换树脂在有机分析与生化分析中的应用。     

阴离子交换树脂催化醇的氰乙基化反应

利用阴离子交换树脂为催化剂，进行了醇的氰乙基化反应，对影响反应的诸因素进行了讨论。     

Hyperbranched Acrylated Aromatic Polyester Used as a Modifier in UV-Curable Epoxy Acrylate Resins

The viscosity,the shrinkage degree and the photopolymerization rate of the epolxy acrylate(EB600) blended with hyperbranched acrylated aromatic polyester(HAAPE) were investigated.The addition of HAAPE into EB600 largely reduces the viscosity of the blend formulation and the shrinkage degree.For example,EB600 resin with 50% weight fraction of HAAPE has the 1250 cps of the viscosity and 2.0% of shrinkage degree,while the pure EB600 resin has 3000 cps of the viscosity and 10.5% of shrinkage degree.The photopolymerization rate of the resin is also promoted by HAAPE addition.The good miscibility between HAAPE and EB600 was also observed from the dynamic mechanical analysis.The tesile,flexural and compressive strength,and the thermal properties of the UV cured films are greatly improved.     

胺类拆分剂从水溶液中拆分外消旋有机酸的研究

具有光学活性的化学物质目前已在药物、食品、饮料、农药等领域得到了广泛的应用,需求日益增长,但化学合成的产物多为无活性的外消旋体(混合物、化合物或固体溶液),要从中得到单一对映体必须进行拆分,非对映体盐结晶法是目前工业应用最广泛的一种拆分技术,其原理是采用一种光学活性物质与外消旋体反应生成一对非对映立体异构体,依据两者在特定溶剂中的溶解度差异实现拆分.该技术尤其适合于外消旋的有机酸、有机碱的拆分,有关这方面拆分实例的报道较多[1～3].但迄今为止,还没有该技术系统的规律性研究报道.本文以若干外消旋有机酸为对象,试图通过以水为溶剂的拆分实验研究,探讨有机酸拆分过程的特性,从而为非对映体盐结晶拆分技术规律性的研究及外消旋有机酸拆分过程工业化的实施创造条件.     

流动注射离子选择电极法自动测定阳离子交换树脂交换容量的研究

基于流动注射离子选择电极法(FIA-ISE)测定痕量Na 原理,建立了一种能自动测定阳离子交换树脂各种交换性能的方法,对影响阳阳离子交换树脂交换容量的各种因素进行考察,筛选出凝胶型强阳离子交换树脂(SACR)交换性能测定的最佳条件:微型交换柱内径3.0mm、长80mm;树脂填充量0.1951g;再生剂HCl浓度为3.0%,其流速为0.90mL/min(7.64m/h),再生剂耗量350mL/g(干树脂);样品为20mg/LNa 溶液,其流速为1.50mL/min;实现了一次测定同时获得SACR的工作交换容量、平衡交换容量、全交换容量、交换速率和树脂利用率。与ASTM法进行对照实验,其结果相关性良好(r=0.9922)。