Na2O—Al2O3—B2O3—SiO2系统溶胶,凝胶涂层的振动光谱研究

本文用振动光谱分析了Ｎａ２Ｏ－Ａｌ２Ｏ３－Ｂ２Ｏ３－ＳｉＯ２系统溶胶中的化学反应和用浸渍法制备的凝胶涂层结构。结果表明：部分硼、铝在溶胶陈化初期就与Ｓｉ（ＯＣ２Ｈ５）４的水解或缩聚产物反应形成线性聚合物，宜于浸涂。热处理时涂层中继续形成Ｓｉ－Ｏ－Ｓｉ、Ｓｉ－Ｏ－Ａｌ和Ｓｉ－Ｏ－Ｂ键；基本结构单元为［ＳｉＯ４］、［ＢＯ４］、［ＢＯ３］和［ＡｌＯ４］。     

Si－C－O－N系统相稳定性及反应烧结制备原位SiC（p）复合ZAS材料

给制了Ｓｉ－Ｃ－Ｏ－Ｎ系统平衡状态下相稳定性与Ｎ２分压和Ｏ２分压以及相稳定性与Ｎ２分压和ＳｉＯ分压的关系图；以此为指导，将原位复合引入到反应烧结锆莫来石（ＺＡＳ）材料中，制备了含原位（ｉｎ－ｓｉｔｕ）ＳｉＣ（ｐ）的ＺｒＯ２ＳｉＣ（ｐ）、ＺｒＯ２－３Ａｌ２Ｏ３·ＺＳｉＯ２－ＳｉＣ（ｐ）－ＳｉＣ（ｐ）复合材料。研究了烧结温度、时间、碳添加量、成型压力等工艺因素对烧结ＺｒＳｉＯ４－Ｃ体系中原位ＳｉＣ生成量的影响，并观察了试样的显微结构。     

氧化反应结合SiC基陶瓷的制备与性能

本文采用反应结合制备方法,通过对坯体进行预氧化使ＳｉＣ颗凿表面氧化形成ＳｉＯ２,而后在烧成中与添中剂ＡＩ２Ｏ３－Ｙ２Ｏ３反应,使坯体气化率减少,制备了多孔ＳｉＣ基陶瓷。文章探讨了坯体中ＳｉＣ的氧化特征、反应结合过程和相变化以及它们对烧结体性能的影响。     

ZrO_2_-3Al_2O_3-2Sio_2/SiC_n纳-微米复相陶瓷的反应烧结技术

概述复相陶瓷和纳米陶瓷的主要内容和机理,介绍反应烧结ＺｒＯ２－３Ａｌ２Ｏ３·２ＳｉＯ２－Ａｌ２Ｏ３／ＳｉＣｎ纳米复相陶瓷技术的研究内容、技术路线、工艺原理和发展前景。     

不同方法制备的高纯SiO2纤维的结构及其形成

用Ｒａｍａｎ光谱和Ｘ射线径向分布函数研究了高纯石英熔融法、酸沥滤法和溶胶－凝胶法三种不同方法制取的高纯ＳｉＯ２纤维的结构。结果表明，不同方法制备的ＳｉＯ２纤维中的断键数目相差很大，并且都远高于块状石英玻璃，断键上连接的原子团也与制备方法有关。径向分布函数表明，沥滤法纤维中存在一种Ｓｉ－Ｏ－Ｓｉ连接，其Ｓｉ－Ｓｉ原子间距分布于近邻Ｓｉ与次近邻Ｓｉ之间。结合不同制备方法的特点对各种纤维结构的形成机理进     

SiO_2微粉中温结合机理的研究

本文研究了ＳｉＯ２微粉、ＳｉＯ２微粉分别与铝酸钙水泥、ｐ－Ａｌ２Ｏ３、ＭｇＯ的混合粉体在３５０℃－１２００℃之间的显微结构。结果表明：ＳｉＯ２微粉及其与其它水化物形成的网状键是高技术浇注料中温强度较高的主要原因。     

Si3N4粉末在空气中的氧化反应方式

本文以ＳｉＮ４粉末作为研究对象，首次采用化学分析的方法发现在Ｓｉ３Ｎ４的氧化过程中有ＮＯ气体生成，打破了传统的Ｓｉ３Ｎ４氧化生成的气态产物只有Ｎ２的看法。采用Ｈ２ＳＯ４＋ＨＮＯ３的混合液作为ＮＯ的吸收液，以ＫＭｎＯ４作为氧化剂，用氧化－－还原滴定法对ＮＯ进行检测。并利用ＸＲＤ和ＸＰＳ分析了Ｓｉ３Ｎ４粉末表面氧化层的组成。根据实验结果和热力学分析，探讨了Ｓｉ３Ｎ４粉末在空气中的氧化反应方式。     

Si－C－O－N系统相稳定性及制备C－SiC纤维和SiC涂层的研究

根据Ｓｉ－Ｃ－Ｏ－Ｎ系统的相稳定性计算，绘制了于平衡状态下相稳定性与Ｎ＿２分压和Ｏ＿２分压以及相稳定性与Ｎ＿２分压和ＳｉＯ分压的关系图，发展了以气态ＳｉＯ与碳纤维反应将碳纤维转变为ＳｉＣ纤维，以及气态ＳｉＯ与ＣＯ反应于碳纤维上形成ＳｉＣ涂层的新方法。本文介绍这两种方法的工艺原理和主要实验结果。     

Si—C—O—N系统相稳定性及制备C—SiC纤维和SiC涂层的研究

根据Ｓｉ－Ｃ－Ｏ－Ｎ系统的相稳定性计算，绘制了于平衡状态下相稳定性与Ｎ２分压和Ｏ２分压以及相稳定性与Ｎ２分压和ＳｉＯ分压的关系图，发展了以气态ＳｉＯ与碳纤维反应将碳纤维转变为ＳｉＣ纤维，以及气态ＳｉＯ与ＣＯ反应于碳纤维上形成ＳｉＣ涂层的新方法。本文介绍这两种方法的工艺原理和主要实验结果。     

玻璃表面的FeCl3浸渍层在碱液中的稳定性

本文通过玻璃受碱侵蚀的失重，侵蚀液的原子吸收光谱分析，Ｘ射线光电子能谱分析，研究了ＦｅＣｌ３表面浸渍层在碱溶液中的稳定作用，玻璃在碱液中侵蚀时，Ａｌ２ｐ和Ｓｉ２ｐ电子结合能降低，这是因为ＯＨ＾－对玻璃表面的侵蚀引起了玻璃骨架中Ｓｉ－Ｏ－Ｓｉ和Ａｌ－Ｏ－Ａｌ键的断裂，表面生成了铝酸盐和硅酸盐凝胶。ＦｅＣｌ３对玻璃表面的浸渍作用割断了碱对玻璃表面的直接作用，因而具有抗碱侵蚀能力。     

Hydrogenation of brown coal: IV Model compound studies and mechanistic considerations

A series of lignin-related phenyl, benzyl and alkyl ethers have been reacted with hydrogen in the presence of iron (II) acetate and tin metal as additives. Iron reduced the rate of reaction of the phenyl ethers and increased the rate of reaction of the benzyl and alkyl ethers compared to the reactions without additive. Tin decreased the rate of reaction of the phenyl and benzyl ethers and had no effect on the reaction of the alkyl ether. Neither iron nor tin changed the products from the reactions of the ethers compared to the reactions without additive. The results are discussed in terms of the use of iron and tin compounds as additives in coal liquefaction reactions.     

Kinetik und Mechanismus der Reaktion von Arylisocyanaten mit Alkylhydroperoxiden

Kinetics and Mechanism of the Reaction of Aryl Isocyanates with Alkyl Hydroperoxides Sec-alkyl peroxycarbamates, prepared from phenyl isocyanate and sec-alkyl hydroperoxides, are instable at normal temperatures and decompose to yield ketones, carbon dioxide and aniline which reacts further to diphenylurea. The reactions of phenyl isocyanate with tetraline hydroperoxide, t-butyl hydroperoxide, aniline, and tert.-butanol in dioxane have been studied kinetically and the catalytic constants of diazabicyclooctane, triethylamine, and stannous octoate as catalysts have been determined. Rate constants of the reactions with hydroperoxides decrease with increasing hydroperoxide concentration caused by association of the catalyst with the hydroperoxide. Compared to their basicities, alkyl hydroperoxides are very reactive towards isocyanates.     

Comparison of the reactions of organic bromides and p-toluene sulphonates with polymeric anions

Alkyl bromides and tosylates were shown to react quantitatively with the living α-methylstyrene tetramer to yield the dialkyl adduct. Alkyl bromides also reacted with α-methylstyrene and lithium in THF to yield the dimeric adduct quantitatively, whereas only about 10% yield of this product was obtained with alkyl tosylate. This difference in behaviour was interpreted in terms of the different adsorptive powers of the two alkyl salts onto lithium metal. Aryl (phenyl) bromides and tosylates reacted with the tetramer to give only low (<5%) yields of the diaryl adduct and in both cases low molecular weight poly(α-methylstyrene) was produced. Benzene was also formed with phenyl bromide and the reaction was explained in terms of a transmetallation process. With the tosylate, the presence of phenol indicated that scission occurred at the SO₂Obond. The reactions of these reagents with α-methylstyrene and lithium in THF both yielded poly(α-methylstyrene) and phenyl bromide was quantitatively converted into biphenyl. Reactions controlled by competitive adsorption were invoked to explain these findings.     

Applications of phase-transfer catalytic reactions to fatty acids and their derivatives: Present state and future potential

Phase-transfer catalysts (PTC), which accelerate reactions between liquid(organic)-liquid(water) and liquidsolid heterogeneous states, have been investigated and developed. Several processes with PTC have succeeded in industrial processes involving fatty acids and their derivatives. For example, preparation of fatty alkyl glycidyl ethers, from which fatty alkyl glyceryl ethers and their derivatives can be obtained, has been carried out with PTC. However, some problems remain to be solved. For example, preparation of the fatty alkyl glycidyl ether by a PTC reaction was considered, but typical problems to be solved included: (i) how to reuse or recover the catalysts; (ii) how to control the heterogeneous reaction without obstacles to produce useful chemical materials; (iii) how to satisfy the environmental requirements for the catalysts; and (iv) are there more effective catalysts? We address these problems based on our own experiences with phase-transfer catalytic Williamson ether syntheses of fatty alkyl glycidyl ethers. Moreover, we describe recent developments in phase-transfer catalytic reactions related to oleochemistry, such as transition metal-catalyzed reactions of long-chain olefins in liquid(organic)-liquid(water) or liquid-solid heterogeneous states. Based on these results, we have considered the potential of PTC as a synthetic tool in oleochemistry.     

十二烷基/苯基硅油的合成与性能研究

通过调整和优化高含氢硅油（UC202）,甲基苯基混合环体(DMe,Ph)、六甲基二硅氧烷（MM）和1-十二烯原料配比和制备工艺,合成一系列具有不同配比的烷基/苯基共改性硅油（PAPMS）,并考察了合成工艺对PAPMS的热性能、密度、黏度及黏度指数、与矿物油的相容性以及对矿物油抗磨性能的影响。结果表明：苯基的引入可提高硅油的热稳定性;长链烷基的引入提高了PAPMS的残炭率和黏度,并能使黏度指数降低;烷基的含量为0.90 mmol/g的PAPMS可与矿物油互溶,将其以10wt.%的量加入矿物油中,可使矿物油的磨斑直径从0.64mm减小到0.55mm。     

Folgeprodukte halogenierter Aldehyde IX. Die Synthese von Dialkyl-1,2,2,2-tetrachloräthyl- und Alkyl-phenyl-1,2,2,2-tetrachloräthyl-phosphaten

Derivatives of Halogenated Aldehydes. IX. The Synthesis of Dialkyl-1,2,2,2-tetrachloroethyl- and Alkyl-phenyl-1,2,2,2-tetrachloroethyl Phosphates Dialkyl-1,2,2,2-tetrachloroethyl- ( 3a – t ) and alkyl-phenyl-1,2,2,2-tetrachloroethyl phosphates 3u , v are prepared by reactions of 1,2,2,2-tetrachloroethyl phosphorodichloridate 1 with one mole of an alcohol or phenol to give alkyl(phenyl)-1,2,2,2-tetrachlorethyl phosphorochloridates 2a – k , followed by treatment of the latter with a second alcohol. The n.m.r. spectra of 2 and 3 are discussed.     

Photochemische Reaktionen von Arylglycidethern

Photochemical Reactions of Arylglycidyl Ethers The absorption, fluorescence and phosphorescence spectra, respectively, of arylglycidyl ether 1 correspond to those of other alkyl aryl ethers. Also the photolysis product distribution (λ = 254 nm) is in agreement with a normal ether photolysis. Furthermore, photoinduced epoxy ring opening takes place giving homopolyaddition oligomers and in methanolic solution also CH₃OH addition products. These reactions can be explained using the model of bichromophoric molecules with the ArO-chromophore as donor and the epoxy ring as acceptor. The calculations based on this model are in agreement with the experimental data. In the aromatic nucleus halogene substituted 1 were dehalogenated with high quantum yield (0.25 in the case of bromo substituted compound 1g ). The quantum yields of the ArO-C-bond scission are about 0.08 independently of the aromatic ring substituents. As indicated by sensitization and quenching experiments, respectively, with aromatic hydrocarbons the photo reactions proceed via S₁ state. It was found that phenol quenches the photodegradation of 1 very efficiently. Excited methyl phenyl glycerol ether 5a reacts with phenyl glycidylether 1a in its ground state producing oligomers.     

Synthesis and gas permeability of ester substituted poly(p-phenylene)s

Polymerizations of various ester substituted 2,5-dichlorobenzoates [substituent: linear alkyl groups (1a-f), branched alkyl groups (1g-l), cyclohexyl groups (1m-o), phenyl groups (1p-r), and oxyethylene units (1s-v)] were investigated with Ni-catalyzed/Zn-mediated system in 1-methyl-2-pyrrolidone (NMP) at 80 °C. Most of monomers bearing linear and branched alkyl groups successfully polymerized to give relatively high-molecular-weight polymers (M_n = 10,000-20,800). However, the molecular weight of the polymer having eicocyl groups was low because of steric hindrance of long alkyl chain. The polymerizations of cyclohexyl 2,5-dichlorobenzoate and phenyl 2,5-dichlorobenzoate produced low-molecular-weight polymers, while the polymerizations of monomers with alkyl cyclohexyl and alkyl phenyl groups proceeded to afford polymers with relatively high-molecular-weights. The polymers possessing oxyethylene units were obtained, but the molecular weights were low when the oxyethylene chains were long. The gas permeability of membranes of poly(p-phenylene)s with alkyl chains increased as increasing the length of alkyl chain. The membranes of poly(p-phenylene)s with phenyl groups and oxyethylene units exhibited high densities and relatively low gas permeability. However, the CO₂/N₂ separation factor of membrane of poly(p-phenylene) having oxyethylene units was as large as 73.6.     

Surface properties of linear alkyl benzene sulfonates in hard river water

Surface properties of a series of highly purified linear alkyl benzene sulfonates were extensively studied in hard river water. The effects of water hardness, alkyl chain length and position of the phenyl sulfonate group in the molecule on such surface properties as pC₂₀, critical micelle concentration (CMC), γ_CMC, CMC/C₂₀ ratio, and minimum area per molecule at the interface are discussed in detail. The position of phenyl sulfonate group in the molecule was found to have a pronounced effect on the CMC, γ_CMC value, CMC/C₂₀ ratio, and, to the contrary, a relatively small effect on the pC₂₀ value. The linear relationship between pC₂₀ or-log CMC, and m, the number of carbon atoms in the alkyl chain, was found for surfactants with the phenyl sulfonate group either at the terminal position or at the more central position in the molecule. γ_CMC decreases but the CMC value increases, when the position of phenyl sulfonate group moves from the terminal toward a more central position of the molecule, reflecting the “Hartley Effect” resulting from the branched alkyl chain.     

High resolution glass capillary columns with chemically bonded stationary phases: application to the gas chromatographic analysis of sterols and steroids in biological extracts

A new approach has been developed for the preparation of highly stable glass capillary columns using irreversible bonding of polysiloxane polymers to the glass surface. The general procedure involves (a) synthesis of reactive linear polysiloxanes from variously (alkyl, aryl) substituted dichlorosilanes through homologous or heterologous polymerization under alcaline aqueous conditions, and (b) covalent condensation of the polymers to a properly prepared glass capillary surface at high temperature. The principle has been first applied to the successful preparation of apolar gas chromatographic systems (methylpolysiloxanes), then extended to the obtention of polar systems (methyl phenyl polysiloxanes). The flexibility of the approach is demonstrated by the possibility of obtaining stationary phases of various and controlled polarity (i.e., extent of phenyl substitution), tailor-made to a given analytical problem. These gas Chromatographic systems appear to be remarkably stable both with time and temperature up to 300 C and compare favorably to existing systems for their high resolution properties. These columns have been satisfactorily used in the last years for the analysis of sterols and steroids of biological origin and most extensively in the study of urinary steroid metabolite in humans under pathological conditions.