过硫酸盐和N,N,N′,N′-四甲基乙二胺体系引发烯类聚合机理的研究

<正> 过硫酸盐和N,N,N′,N′-四甲基乙二胺(TMEDA)体系用作烯类聚合的引发剂已有报道。本文报道该引发体系的反应机理。1.实验方法     

Voltammetric Antioxidant Analysis in Mineral Oil Samples Immobilized into Boron‐Doped Diamond Micropore Array Electrodes

Mineral oil microdroplets containing the model antioxidant N,N‐didodecyl‐N′,N′‐diethyl‐phenylene‐diamine (DDPD) are immobilized into a 100×100 pore‐array (ca. 10 μm individual pore diameter, 100 μm pitch) in a boron‐doped diamond electrode surface. The robust diamond surface allows pore filling, cleaning, and reuse without damage to the electrode surface. The electrode is immersed into aqueous electrolyte media, and voltammetric responses for the oxidation of DDPD are obtained. In order to further improve the current responses, 20 wt% of carbon nanofibers are co‐deposited with the oil into the pore array. Voltammetric signals are consistent with the oxidation of DDPD and the associated transfer of perchlorate anions (in aqueous 0.1 M NaClO₄) or the transfer of protons (in aqueous 0.1 M HClO₄). From the magnitude of the current response, the DDPD content in the mineral oil can be determined down to less than 1 wt% levels. Perhaps surprisingly, the reversible (or midpoint) potential for the DDPD oxidation in mineral oil (when immersed in 0.1 NaClO₄) is shown to be concentration‐dependent and to shift to more positive potential values for more dilute DDPD in mineral oil solutions. An extraction mechanism and the formation of a separate organic product phase are proposed to explain this behavior.     

Synthesis and properties of soluble trifluoromethyl‐substituted polyimides containing laterally attached p‐Terphenyls

A new fluorinated diamine monomer, 2′,5′‐bis(4‐amino‐2‐trifluoromethylphenoxy)‐p‐terphenyl, was synthesized from the chloro‐displacement of 2‐chloro‐5‐nitrobenzotrifluoride with the potassium phenolate of 2,5‐diphenylhydroquinone, followed by hydrazine palladium‐catalyzed reduction. A series of trifluoromethyl‐substituted polyimides containing flexible ether linkages and laterally attached side rods were synthesized from the diamine with various aromatic dianhydrides via a conventional two‐step process. The inherent viscosities of the poly(amic acid) precursors were 0.84–1.26 dL/g. All the polyimides afforded flexible and tough films. The use of 4,4′‐oxydiphthalic anhydride and 2,2′‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride produced essentially colorless polyimide films. Most of the polyimides revealed an excellent solubility in many organic solvents. The glass‐transition temperatures of these polyimides were recorded between 254 and 299 °C by differential scanning calorimetry, and the softening temperatures of the polymer films stayed in the range of 253–300 °C according to thermomechanical analysis. The polyimides did not show significant decomposition before 500 °C in air or under nitrogen. These polyimides also showed low dielectric constants (2.83–3.34 at 1 MHz) and low moisture absorption (0.4–2.2%). For a comparative study, a series of analogous polyimides based on the nonfluorinated diamine 2′,5′‐bis(4‐aminophenoxy)‐p‐terphenyl were also prepared and characterized. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1255–1271, 2004     

铵基乙酸盐型两性表面活性剂的合成

以月桂酸、硬酯酸和羟乙基乙二胺为原料，经环化、还原和季铵化合成了４种新化合物，对其中２种按基乙酸盐两性表面活性剂的表面张力、临界胶束浓度（ｃｍｃ）和泡沫性能做了测定。     

Oxidative macrocyclocondensation of 3,4-diaminofurazan and 4,4′-diamino-3,3′-azofurazan with dibromoisocyanurate. Crystal structures of hexa- and octadiazenofurazan macrocycles

The oxidative cyclocondensation of 3,4-diaminofurazan and 4,4-diamino-3,3-azofurazan with dibromoisocyanurate afforded macrocyclec polydiazenofurazans. The reaction can be directed towards the formation of both the four-membered cycle alone or the three-, six-, and eight-membered macrocycles.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1250–1254, May, 1996.Deceased in 1995.     

3,3′-二氨基查尔酮的合成

由硝基苯甲醛和硝基苯乙酮经C laisen-Schm idt缩合制得3,3′-二硝基查尔酮,再用FeC l3-NH2NH2.H2O-C体系将其还原成3,3′-二氨基查尔酮。所得产品经元素分析、熔点、IR和1H NMR测试确认,讨论了影响产品收率的因素。收率为78.6%。     

Microwave-assisted acid hydrolysis of toluene diamine conjugates in urine samples for biomarkers in toluene diisocyanate analysis

Toluene diamines (TDAs) in urine have been used widely to determine the amount of toluene diisocyanate (TDI) absorbed by humans. Conventional hydrolysis to prepare a sample of urine takes approximately 16 h. An attempt is made to apply microwave-assisted heating (MAH) to reduce the duration of analysis. Urine collected from rats exposed to a mixture of 2,4- and 2,6-TDI was diluted with non-exposed human urine 1/1250-, 1/500- and 1/250-fold. The urine samples were hydrolyzed by both conventional heating and MAH. The hydrolysis efficiency obtained using MAH significantly exceeded that obtained using conventional heating. Hydrolysis by MAH required only 20 min, 48 times faster than with conventional heating. The use of the MAH method in hydrolysis was demonstrated to be reproducible, timesaving and efficient technique in measuring the concentration of urinary TDAs.     

Synthesis of anew siloxane-containing diamine and related polyimide

A novel siloxane-containing diamine, bis[4-(p-aminophenoxy)phenoxy]dimethylsilane (APPMS), was successfully synthesized in three steps using hydroquinone as starting material, which was reacted with 4,4'-oxydiphthalic anhydride (ODPA) via a conventional two-step thermal or chemical imidization method to produce a new siloxane-containing polyimide. The resulting polyimide exhibited excellent solubility, and film-forming capability.     

乙二醇催化氨化合成乙二胺

为了探索乙二胺绿色合成的新工艺,采用自制的负载型双组分复合金属氧化物Ni O/Cu O/Al2O3为催化剂,对乙二醇进行催化氨化制备乙二胺,用气相色谱法对反应物进行分析检测,采用X射线衍射仪(XRD)、X射线光电子能谱分析仪(XPS)等技术手段对催化剂结构进行了表征。通过考察催化剂组成、物料比、温度和时间等因素对反应的影响,确定了合成乙二胺的最佳工艺条件:催化剂活性组分n(Ni)∶n(Cu)=3∶1、催化剂加入量3%、氨醇质量比4∶1、反应温度180℃、反应压力0.6 MPa、反应时间4 h,乙二胺的选择性达56.7%,乙二醇转化率达68.6%。与传统的二氯乙烷法相比较,本工艺更清洁友好。     

大核树枝状大分子的合成及其凝血、溶血性能研究

从 8 0年代中期开始 ,Ｔｏｍａｌｉａ、Ｎｅｗｋｏｍｅ、Ｆｒｅｃｈｅｔ等对树枝状大分子开展了卓有成效的研究 ,合成了多种结构的树枝状大分子[1 ] ,并对它们的应用进行了积极的探讨 .在数枝状大分子的合成方面 ,寻找新的多官能团引发核就是一个研究热点 ,例如采用大分子核 ,Ｆｒｅｃｈｅｔ等采用聚乙二醇作为核用收敛法合成了聚芳醚和聚芳酯树枝状大分子[2 ,3] ,为嵌段共聚增添了新的内容 .而Ｔｏｍａｌｉａ等以氨和乙二胺等小分子为核合成的聚酰胺 胺类树枝状大分子呈粘糊状[4] ,取样、称量等操作很麻烦 ,其应用也受到限制 .聚乙二醇无毒…