烷氧基化反应技术简介

对烷氧基化反应的釜式烷氧基化反应器、循环喷雾的Press烷氧基化反应器、喷射式回路反应器和连续管式反应器进行了介绍,对比了各自的特点。     

烷氧基化聚合反应器的研究进展

系统介绍了几种已经工业化应用的烷氧基化聚合反应器,如管式、降膜式、釜式、意大利Press、瑞士Buss、Linde以及外循环釜式等反应器的优缺点,同时介绍了近年来日本、欧美和中国大陆主要烷氧基化聚合反应器的结构及特点。     

水滑石的制备和在烷氧基化酯合成反应中应用

水滑石是一类双金属层柱状化合物,因其具有特殊的层间离子交换性能和结构记忆效应,近年来以水滑石结构为前驱物制备复合氧化物的途径越来越引起人们的重视.综述了水滑石的制备以及在烷氧基化酯合成反应中的应用,指出水滑石由于特殊的结构在催化方面将扮演重要的角色.     

我国烷氧基化装置的工艺进展和评述(待续)

介绍了烷氧基化生产工艺,对目前国内使用的烷氧基化装置的工艺、设备和自动控制进行了对比分析。评述了不同工艺装备的技术特点,对选择不同装备的烷氧基化装置进行分析并提出了国产化第五代烷氧基化工艺装备的设计思想。     

1-甲氧基-2-甲基萘的合成研究

以2-甲基萘为原料,在惰性的卤代烃溶剂中低温下进行溴化反应,制备1-溴-2-甲基萘;溴化产物在碘化亚铜催化下,和甲醇钠进行烷氧基化反应制得1-甲氧基-2-甲基蔡。产品纯度〉99％（GC）,总收率87．4％．产品结构经MS和^1H NMR确认。考察了反应条件对产品收率和纯度的影响。     

植物油多元醇开发的技术进展

介绍了国内外市场上的聚氨酯用植物油多元醇产品,综述了醇解、烷氧基化、植物油臭氧氧化、植物油环氧化和羟基化、植物油氢甲酰化5种工艺路线合成植物油多元醇的研究进展,并对我国植物油多元醇的发展提出建议。     

溴化环氧树脂阻燃剂应用综述与发展展望

综述了溴化环氧树脂产品的分类和应用概况,具体介绍了溴化环氧树脂在PBT、PET、ABS、PA等产品中的应用情况,并结合我国的实际情况对溴化环氧树脂的应用提出了一些设想和建议.     

单烷氧基钛酸酯偶联剂在涂料中的应用

综述了单烷氧基钛酸酯偶联剂的分类及偶联机理,介绍了其用法、用量及其在使用过程中可能发生的水解缩合反应,并以国内外常用的3类偶联剂产品为实例,展示了单烷氧基钛酸酯偶联剂在涂料中的应用前景。     

Cu(I)卤化物催化合成烷基芳基醚的研究

本文简要地介绍了未被活化芳烃的烷氧基化反应，对其反应机理、应用范围、影响因素等作以综述。     

推进烷氧基化绿色工艺发展,培养学生专业思维能力——以甲氧基化反应的进步为例

基于研究成熟的非活化溴代芳烃甲氧基化反应的机理,借助锂离子亲氧性,一种廉价、具有原子经济性、洁净高效的绿色反应体系被应用到铜催化非活化溴代芳烃的短链烷氧基化反应中,且进一步用于对药物发现有重要意义的氟代烷基芳基醚化合物的绿色合成。教学中介绍这一渐进的工艺发展历程,有助于逐步培养学生的创新性专业思维能力。     

醚化封端聚醚的研究进展及应用

重点论述了醚化封端聚醚的主要合成方法、醚化封端聚醚的分子结构对产品特性的影响,以及近年来醚化封端聚醚的技术进展。并通过实例介绍了醚化封端聚醚在清洗、纺织印染、食品加工及在合成聚醚改性有机硅等领域的应用。     

Preparation and Characterization of Aminopropylsilatrane Endcapped Polyimide Films

γ-Aminopropylsilatrane (APS)/γ-aminopropyltriethoxysilane (APTES) end capped polyimide films were prepared by thermal imidization method. Polyamic acid (PAA) was prepared by the reaction of 4,4′-oxydianiline (ODA) with 4,4′-oxydipthalicdianhydride (ODPA) using dimethylacetamide (DMAc) as solvent. The end group of prepared PAA was capped by different percentage of APS/APTES. The polyimide films were characterized by different advanced instrumental techniques for chemical/physical properties. APS end capped PI films show better thermal and mechanical properties and air permeability than APTES end capped polyimide films.     

封端型聚醚改性聚硅氧烷非离子表面活性剂的合成

以低含氢硅油、α-烯丙基聚醚等为原料,经烷基封端、硅氢加成等反应制备了封端型聚醚改性聚硅氧烷非离子表面活性剂,讨论了温度、催化剂以及聚醚结构等对封端率的影响。结果表明,采用以氢氧化钠和碳酸钠制备的缓释性复合碱为催化剂的一步法封端工艺,在反应温度25~65℃条件下,α-烯丙基聚醚的烷基封端率可达85%以上。封端型聚醚改性有机硅表面活性剂可用于单组分聚氨酯密封胶、高回弹和软质聚氨酯泡沫的泡沫稳定剂。     

表面修饰氧化亚铅纳米颗粒的制备及其抗磨性能研究

以硬脂酸铅为单源前驱体,成功制备出硬脂酸修饰的氧化亚铅纳米颗粒,用透射电子显微镜、X-射线粉末衍射仪、红外光谱仪等仪器对其进行了结构表征,并在四球摩擦试验机上测试了其抗磨性能。结果表明:所制备的Pb2O纳米颗粒大小均匀,表面修饰层与纳米颗粒表面之间发生化学键合作用,其作为润滑油添加剂具有良好的抗磨能力。     

Solid state hydrolysis of bisphenol-A polycarbonate. I. Effect of phenolic end groups

Solid samples of a nonhydrolytically stabilized bisphenol-A polycarbonate were hydrolyzed at 125°C and 1.4 atm of steam. IR and UV techniques were used both to estimate the degree to which the unhydrolyzed polymer is capped by a chain-terminating agent and to determine the rate of hydrolysis as indicated by the formation of new phenolic end groups. The rate of formation of low-molecular-weight products, particularly bisphenol-A, was estimated by gel permeation chromatography studies. The combined results suggest that the degree of end-group capping is an important factor in the hydrolytic stability of the solid polymer. A model consistent with these results is proposed.     

Phase separation phenomena in aqueous solutions of amphiphilic poly(ethylene oxide) star polymers

Three- and four-armed star polymers with poly(ethylene oxide) arms capped with hydrophobic end-groups were synthesized from nonylphenoxypoly(ethylene glycol)s and well defined tri- and tetraisocyanates. The latter were hydrosilylation products of m-isopropenyl-,-dimethylbenzyl isocyanate (m-TMI). In aqueous solution the arm ends associate, and above a critical star concentration the mixture phase separates into a dilute phase and a condensed gel phase. Their respective polymer concentrations remain constant as long as the two phases coexist, their volume fractions being proportional to the total polymer concentration. Brookfield viscosity measurements confirm the formation of the gel phase which resembles an amphiphilic hydrogel. It exhibits a high affinity for hydrophobic compounds.     

Electrochemical and UV–Vis/ESR spectroelectrochemical properties of thienylenevinylenes substituted by a 4-cyanostyryl group

The π-electron delocalisation in conjugated thienylenevinylenes bearing arylethenyl chromophores, makes those materials interesting candidates for electro-optic applications. In this study, we report the results of electrochemical and UV–Vis/ESR spectroelectrochemical studies of a pair of thienylenevinylenes substituted by the 4-cyanostyryl group, bearing either a hydrogen, or methyl group terminated α carbons at the peripheral thiophene rings. The reactivity of various functional segments of investigated molecules was assessed by comparing the reactivity of the protected and unprotected counterparts and the behaviour of their electrooxidation products. For the capped derivative, two irreversible anodic redox processes giving electrochemically inactive products were observed, while the uncapped molecule yields electroactive materials already upon its first oxidation step.     

Evidence for high performances of low Pt loading electrodes based on capped platinum electrocatalyst and carbon nanotubes in fuel cell devices

Recently we reported the preparation and electrochemical behaviour of porous electrodes based on the controlled combination of carbon nanotubes and capped platinum nanoparticles towards oxygen reduction. Due to the organic crown of the nanoparticles, the electrodes exhibited low hydrogen underpotential deposition (H upd) electroactive surface areas but significant activity towards oxygen reduction was recorded down to very low platinum loadings of few μg/cm². While the presence of organic stabilizing material, at the surface of the electrocatalyst synthesized by wet chemistry, may be considered as a potential drawback in fuel cell community, we present in this paper results showing that our capped electrocatalyst associated with carbon nanotubes can be used without any pre-treatment and exhibit high performances in fuel cell devices, in spite of low platinum loadings. Beyond the practical interest of such capped nanoparticles in fuel cell technology demonstrated here, fundamental question related to the high performances of the capped electrocatalyst are still opened and are currently under investigation.     

Synthesis of telechelic C60 end‐capped polymers under microwave irradiation

Bromo‐Double‐Terminated polystyrene (Br‐PSt‐Br) and poly(methyl methacrylate) (Br‐PMMA‐Br) with predesigned molecular weight and narrow polydispersity were prepared by atom transfer radical polymerization (ATRP) using the initiating system aa′‐dibromo‐p‐xylene(DBX) / CuBr/2,2′‐bipyridine(bipy). The precursor bromo‐terminated polymers were subsequently functionalized with fullerene C₆₀ using CuBr/bipy as the catalyst system under microwave irradiation (MI). The telechelic C₆₀ end‐capped products were characterized by gel permeation chromatography (GPC), UV‐vis, FT‐IR, TGA, DSC, ¹H NMR, and ¹³C NMR. The results showed that microwave irradiation could significantly increase the rate of fullerenation reaction, and the physical properties and structure of the C₆₀ end‐capped polymers are not modified by the use of the microwave. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 828–834, 2006     

Physical Properties of Low Viscosity Estolide 2-Ethylhexyl Esters

Acetic‐ and butyric‐capped oleic estolide 2‐ethylhexyl (2‐EH) esters were synthesized in a perchloric acid catalyzed (0.05 equiv) one‐pot process from industrial 90 % oleic acid and either acetic or butyric fatty acids at two different ratios. This was directly followed by the esterification process incorporated into an in‐situ second step to provide a low viscosity estolide ester functional fluid. The monoestolide and polyestolides were separated via vacuum distillation (6–13 Pa) at 240–250 °C. The physical properties of these materials were followed throughout the synthetic process and are reported. The final low viscosity acetic‐ and butyric‐capped monoestolide 2‐EH esters had viscosities of 19.9 and 24.2 cSt at 40 °C and 4.8 and 5.5 cSt at 100 °C with viscosity indexes (VI) of 161 and 163, respectively. Both monoestolide esters displayed excellent pour points (PPs). The PPs of the two were as follows: acetic‐capped estolide 2‐EH ester PP = ?45 °C and butyric‐capped estolide 2‐EH ester PP = ?27 °C. The biodegradable short‐capped oleic estolide 2‐EH esters had excellent low temperature properties and should perform well in low viscosity applications.