二烷基磷(膦)酸萃取剂钠盐微乳液的热力学函数

测定了二烷基磷(膦)酸钠盐(NaDEHP,NaEHEHP和NaDTMPP)-醇-有机溶剂-水(或盐溶液)皂化萃取体系微乳液的ΔG~0~→~1(醇从油相转移到界面相的标准自由能变),探讨了萃取剂类型,有机溶剂类型,烷烃碳链长度,醇碳链长度,温度及水相金属离子浓度对热力学函数的影响规律     

二氧化碳: 一种同时提供亲核中心保护和亲电中心活化的试剂 XI:2-取代四氢噻唑的新合成方法

四氢噻唑和正丁基锂反应生成的N-锂代四氢噻唑(2)与二氧化碳作用生成N-羟酸锂盐3; 3然后在叔丁基锂作用下失去2-位质子形成相应的2-位碳阴离子4; 该碳阴离子和一系列亲电试剂反应, 并在酸性条件下除去保护基团得产物-2-取代四氢噻唑7. 在此过程中, 二氧化碳既是氨基的保护基团, 同时又活化了2-位亲电中心.此方法不需分离各步中间体, 产率中等.     

A NOVEL ZWITTERIONIC SILANE COUPLING AGENT FOR NONTHROMBOGENIC BIOMATERIALS

A novel silane coupling agent bearing sulfobetaine group, N,N-diethyl-N-（3-sulfopropyl）-aminopropyl- trimethoxysilane （DESATS）, was first designed, synthesized and characterized. Its solution property was studied by means of dynamic light scattering. DESATS was successfully bonded onto the surface of the glass and proved by ESCA. Platelet adhesion assay in vitro indicated that the nonthrombogenicity of glass slide modified with DESATS is greatly improved.     

Influence of interfacial reaction on interfacial performance of carbon fiber and polyarylacetylene resin composites

The influence of interfacial reaction on interfacial performance of carbon fiber/polyarylacetylene resin composites was studied. For this purpose, vinyltrimethoxysilane containing a double bond was grafted onto the carbon fiber surface to react with the triple bond of polyarylacetylene resin. The reaction between polyarylacetylene resin and vinyltrimethoxysilane was proved by reference to the model reaction between phenylacetylene and vinyltrimethoxysilane. Surface chemical analysis by XPS, surface energy determination from the dynamic contact angle, and the interfacial adhesion in composites was evaluated by interfacial shear strength test as well. It was found that vinyltrimethoxysilane, which can react with polyarylacetylene resin, had been grafted onto the carbon fiber surface. Furthermore, because the reaction between polyarylacetylene resin and vinyltrimethoxysilane took place at the interface, the interfacial adhesion in composites was significantly increased, and the improvement of interfacial adhesion was all attributed to the interfacial reaction.     

Acceleration of silanol condensation of a methacryl-functional silane in the model sizing system

The silanol condensation of hydrolyzed γ-methacryloxypropyltrimethoxysilane (γ-MPS) in the presence of a typical film-forming polymer, poly(vinyl acetate), PVAc, has been studied. The model sizing system, consisting of the hydrolyzates of γ-MPS and PVAc obtained from the alcoholic aqueous solution, is studied using Fourier transform infrared spectroscopy (FT-IR) and size exclusion chromatography (SEC). In the initial stage of silanol condensation of the hydrolyzates of the model sizing system, it has been found that the condensation reaction is accelerated compared with the system that contains no film-former. It has also been found that the structure of γ-MPS oligomer is relatively ordered and less-active for further silanol condensation. The least-square curve-fitting procedure for FT-IR spectra indicates five carbonyl stretching bands, reflecting the hydrogen bonded and the free carbonyl groups of the silane coupling agent and the film-forming polymer.     

Injection Molding of Wood–Fiber/Plastic Composite Foams

This paper investigates the feasibility of injection-molded wood–fiber/high-density polyethylene (HDPE) composite foams that can replace injection-molded HDPE solids in industrial applications. The study applies injection foam molding technology using a physical blowing agent to a wood–fiber/HDPE composite, and examines the effects of the processing parameters on the dimensional and mechanical properties and cell density of the composite foams. In addition, the physical properties and cost of wood–fiber/HDPE composite foams are compared with those of solid HDPE. The experimental results show that wood–fiber/HDPE composite foams that have a 20% weight reduction have superior physical properties, such as density, dimensional properties (68% decrease of shrinkage and 91% decrease of warpage) and mechanical properties (28% increase of Young's modulus). Furthermore, the cost analysis confirms that wood–fiber/HDPE composite foams are much less expensive (by 40%) than HDPE. Therefore, it is concluded that wood–fiber/HDPE composite foams are strong candidates for replacing current injection-molded HDPE products.     

Effect of curing temperature,fibre loading and bonding agent on the equilibrium swelling of isora-natural rubber composites

Isora fibre-reinforced natural rubber (NR) composites were cured at 80, 100, 120 and 150°C using a low temperature curing accelerator system. Composites were also prepared using a conventional accelerator system and cured at 150°C. The swelling behavior of these composites at varying fibre loadings was studied in toluene and hexane. Results show that the uptake of solvent and volume fraction of rubber due to swelling was lower for the low temperature cured vulcanizates which is an indication of the better fibre/rubber adhesion. The uptake of aromatic solvent was higher than that of aliphatic solvent, for all the composites. As the fibre content increased, the solvent uptake decreased, due to the superior solvent resistance of the fibre and good fibre–rubber interactions. The bonding agent improved the swelling resistance of the composites due to the strong interfacial adhesion. Due to the improved adhesion between the fibre and rubber, the ratio of the change in volume fraction of rubber due to swelling to the volume fraction of rubber in the dry sample (V_τ ) was found to decrease in the presence of bonding agent. At a fixed fibre loading, the alkali treated fibre composite showed a lower percentage swelling than untreated one for both systems showing superior rubber–fibre interactions.     

二环己基-18-冠-6异构体A与铀的萃取配合物的结构研究

二环己基-18-冠-6-异构体Δ(dcc)在盐酸体系中萃取UO2Cl2和UCl4时, 形成的配合物晶体的组成分别为(C20H36O6.H3O)2UO2Cl4.2C6H6(1)和(C20H36O6.H3O)2UCl6(2). 结构分析证实, 在1和2中, U(VI)和U(IV)均未与冠醚直接配位, 而是分别形成配阴离子四氯铀铣(II)和六氯化铀(II). 而配阳离子均由冠醚环的三个氧原子与H3^+O以较强的氢键键合, 将H3O^+稳定于冠醚环中, 成为配阳离子dcc.H3O^+. 由静电吸收及Van der Waals力形成稳定的晶体.     

乙酰丙酮基聚苯乙烯在萃取金属离子上的应用

大孔的苯乙烯-二乙烯苯共聚物经氯甲基化后,分别与乙酰丙酮镍、乙酰丙酮钠和四正丁基乙酰丙酮铵三种不同的乙酰丙酮盐反应,可制得聚3-(p-乙烯苄基)戊二酮-[2,4]。其中以由乙酰丙酮镍制得的聚合物最好,除二乙烯苯外,78%左右的苯环乙酰丙酮化了。该聚合物螯合Fe~(3 )和Ni~(2 )的能力与β-二酮基高聚物相仿或稍优。还比较了此类高聚物的物理机械性能。