Organometallic Derivatives of Cyclotriphosphazene as Precursors of Nanostructured Metallic Materials: A New Solid State Method

The cyclic phosphazene trimers [N₃P₃(OC₆H₅)₅OC₅H₄N·Ti(Cp)₂Cl][PF₆] (3), [N₃P₃(OC₆H₄CH₂CN·Ti(Cp)₂Cl)₆][PF₆]₆ (4), [N₃P₃(OC₆H₄-Bu^t)₅(OC₆H₄CH₂CN·Ti(Cp)₂Cl)][PF₆] (5), [N₃P₃(OC₆H₅)₅C₆H₄CH₂CN·Ru(Cp)(PPh₃)₂][PF₆] (6), [N₃P₃(OC₆H₅)₅C₆H₄CH₂CN·Fe(Cp)(dppe)][PF₆] (7) and N₃P₃(OC₆H₅)₅OC₅H₄N·W(CO)₅ (8) were prepared and characterized. As a model, the simple compounds [HOC₅H₅N·Ti(Cp)₂Cl]PF₆ (1) and [HOC₆H₄CH₂CN·Ti(Cp)₂Cl]PF₆ (2) were also prepared and characterized. Pyrolysis of the organometallic cyclic trimers in air yields metallic nanostructured materials, which according to transmission and scanning electron microscopy (TEM/SEM), energy-dispersive X-ray microanalysis (EDX), and IR data, can be formulated as either a metal oxide, metal pyrophosphate or a mixture in some cases, depending on the nature and quantity of the metal, characteristics of the organic spacer and the auxiliary substituent attached to the phosphorus cycle. Atomic force microscopy (AFM) data indicate the formation of small island and striate nanostructures. A plausible formation mechanism which involves the formation of a cyclomatrix is proposed, and the pyrolysis of the organometallic cyclic phosphazene polymer as a new and general method for obtaining metallic nanostructured materials is discussed.     

The Interaction of the Efflux of Solid Propellants with Nozzle Materials

Progress in obtaining solid composite propellants with highest specific impulse caused severe problems with materials such as graphite used in the construction of insulation and nozzles in solid rockets. Refractory metals provide relief but at the expense of the desired and gained performance increase in propellants. On the basis of data obtained by experimental firings and thermodynamic analysis it was demonstrated that the primary cause of graphite removal in solid rocket motor nozzles is dependent on pressure and on chemical attack by certain species of the exhaust gas. The most damaging gases are those which react with carbon to form carbon monoxide. The chamber flame temperature does not directly affect graphite removal. Analysis of data indicates a good correlation of propellant composition and oxygen balance of the initial propellant from which the exhaust gases are generated. Application of these findings make it possible to select propellant formulations with minimum corrosive action on graphite.     

微晶玻璃-金属复合新型装饰材料

本文通过介绍新型装饰材料的发展趋势,对铝塑板、不锈钢金属、微晶玻璃等现有的新型装饰材料进行了分析比较,提出把微晶玻璃与金属复合作为装饰材料使用。最后详细阐述了这种材料的特点,并对其应用进行了展望。     

表面活性剂在固液界面吸附研究的某些新进展

本文综述了离子型表面活性剂以及阳离子与非离子型表达活性剂的混合体系在固液界面吸附情况。     

光敏热显成像材料中组分山嵛酸银与邻苯二甲酸的固相反应动力学

采用液相沉淀法合成了山嵛酸银与邻苯二甲酸的固相反应产物邻苯二甲酸二银,并通过元素分析、ICP-AES、FT-IR等方法对其进行了表征分析.在此基础上,采用X射线衍射K值分析法,在光敏热显成像材料热显影温度范围内(100～123 ℃),研究了山嵛酸银与邻苯二甲酸的固相反应过程.结果表明,山嵛酸银与邻苯二甲酸的固相反应为固态扩散控制过程.在一定的反应时间内,Jander方程能够较好地描述山嵛酸银与邻苯二甲酸的固相反应动力学,反应的表观活化能为84.5 kJ·mol-1,表观频率因子为7.06×107 min-1.在光敏热显成像材料热显影过程中,提高调色剂邻苯二甲酸在涂层中的扩散速度有利于提高其显影速率.     

Applicability of Frozen Gels from Ultra High Molecular Weight Polyethylene and Paraffin Waxes as Shape Persistent Solid/Liquid Phase Change Materials

Ultra high molecular weight polyethylene (UHMW‐PE) physically gels molten paraffin waxes (PW) at concentrations exceeding 0.5 wt.‐%. In the composites the paraffin wax crystallises without destruction of the UHME‐PE gel network. Above the melting transition of the paraffin compound the capillary forces prevent the liquid wax from free flow. The composites can be processed by melt extrusion, and injection moulding above the melting temperature of the gel at 116 °C. The thermal and mechanical properties of these UHMW‐PE/paraffin composites have been characterised regarding their applicability as shape persistent phase change materials (PCM). The UHMW‐PE/PW gels can store, and release enthalpies up to 200 J/g at the melting temperature of the PW. In the gel state the liquid alkane can leave the gel when in direct contact to porous materials, and the gels mechanical strength are lower than that of standard polymers. These drawbacks are proposed to overcome by formation of PCM/polymer, or PCM/metal laminates.

Schematic cross section of a proposed PCM laminate consisting of a polymer top‐ and bottom layer enclosing the UHMW‐PE/paraffin gel.     

利用固体废弃物制备硫铝酸盐水泥的研究进展

硫铝酸盐水泥具有早强、高强、抗冻、抗渗、耐腐蚀和低碱度等优良特性,生产能耗更低.本文对利用固体废弃物为原料制备硫铝酸盐水泥的国内外研究现状进行了介绍,综述了赤泥、脱硫灰渣、城市垃圾焚烧飞灰、粉煤灰等固体废弃物的性能以及对硫铝酸盐水泥熟料水化特性、物相组成、机械强度等性能的影响.最后提出如果能充分有效地利用固体废弃物,硫铝酸盐水泥工业将在实施循环经济和可持续发展战略中具有更大的优势.     

用液晶模板合成有序中介结构的无机材料

讨论了以溶致液晶为模板合成中孔无机材料的新方法,复合的表面活性剂一无机物组合体的结构取决于无物的性质以及它同表面活性剂的静电和立体空间的相互作用。阐明了转录作用和协同作用两种形成机制,转录合成中稳定的、预组织的有机结构被用作无机材料进行沉积的模板;协同合成中,模板是经无机前体与有机分子之间协同作用形成的有机一无机共组合体。说明了通过调节表面活性剂链长、有机添加物、实验温度和反应时间以及助溶剂来控制     

腰果壳油改性摩擦材料用酚醛树脂的研究进展

腰果壳油是天然有机酚化合物,利用其改性摩擦材料用酚醛树脂具有改善材料力学性能和降低成本等优点,本文介绍了腰果壳油的组成及特性,简述了腰果壳油酚醛树脂的制备方法、改性途径及改性树脂用于摩擦材料方面的研究进展,进而展望了该树脂研究的前景。     

水热辅助下MgFe-CO3-LDH的室温固相制备

采用室温固相反应结合水热处理制备出层状双金属氢氧化物(MgFe-CO3-LDH)。利用X射线粉末衍射(XRD)、傅立叶变换红外光谱(FT-IR)、热重-差热分析(TG-DTA)和扫描电子显微镜(SEM)等方法对产物进行了表征。研究结果表明,随着Mg2+/Fe3+物质的量比的增加,所得样品的结构规整性及热稳定性均有所增加。     

Study of the Processing and Mechanical Properties of In Situ Composite Materials of Thermoplastics with Thermotropic Liquid Crystalline Polymers

By blending thermoplastics (TPs)—polycarbonate (PC) and polyethersulfone (PES)—with thermotropic liquid crystalline polymers (TLCPs)—KU9221 and KU9231—and then extruding the blends to form fibers, the in situ reinforcing characteristics were studied. The injection experiment of blends was compared with the extrusion experiment. According to the experimental results, in situ reinforcing characteristics of these processes were analyzed theoretically. These researches have come to some important conclusions. TLCP domains can be transformed to form fibers that are oriented in the direction of flow during processing; these TLCP microfibers result in improved mechanical properties of the TP/TLCP blends. The extruding flow is more effective in orienting TLCP domains and results in better in situ reinforcement than that of injection molding, and the extruded fibers have better mechanical properties. The mechanical properties of the blend fibers are improved greatly with increasing tensile ratio of melt drawing and the content of TLCPs.     

新型无机铝离子/蒙脱石复合材料催化合成DOP的研究

研究了新型无机铝离子 /蒙脱石复合材料催化剂的制备方法 ,最佳合成条件为 0 2mol/L三氯化铝水溶液与 0 1mol/L氢氧化钠水溶液的体积比为 1∶5 ;保温时间 48h ;保温温度 95℃ ;搅拌时间为 4d ,在此最佳合成条件下制得的催化剂用于合成DOP的酯化率可达 92 %。并对催化剂进行了X射线能谱表征。     

Phosphoryl Triamide Polymers Revisited: Identification of Structural Units with ESI-MS/MS and Solid State NMR

The thermal condensation of phosphoryl triamide was reinvestigated and analyzed with ESI-MS as well as ³¹P- and ¹H-NMR spectroscopy in the solid state and in solution. Our results indicate that strongly crosslinked polymers are formed even at temperatures lower than 300 °C; and, furthermore, evidence for facile partial hydrolysis of oligomeric condensation products on contact with water has been established using ESI-MS/MS.     

In Situ Incorporation of Liquid Polysulfide Oligomer Modified MoS2 into Polysulfide Rubber (PSR) as Solid Crosslinker with Greatly Improved Dispersion Ability and Interfacial Interaction

Polysulfide rubber (PSR) is a versatile sealing material, but suffers from poor mechanical properties, which can be solved by increasing the crosslinking density and introducing fillers. In this study, functionalized molybdenum disulfide (MMoS₂) by in situ incorporation with different thiol-containing compounds is obtained. On the basis of the optimum content of 0.5 wt.%, the performance of MMoS₂/PSR is systematically studied. The results show that the interfacial interaction between MMoS₂ and the matrix is improved. In particular, PSR reinforced by MoS₂ modified with polysulfide oligomer (MoS₂-LPO) behaves the most excellently. Its solvent resistance and crosslink density are also improved by 14.2% and 39.4%, respectively. The storage modulus of MoS₂-LPO/PSR is 394% higher than that of the unmodified one. This is attributed to the MoS₂-LPO playing the role of filler and large-sized solid crosslinker at the same time. Through broadband dielectric spectroscopy (BDS), it is determined that MoS₂-LPO/PSR has the longest relaxation time due to the stronger interfacial interaction. In order to understand the effect of interfacial interaction between MoS₂ and PSR on the properties of the composites more clearly, MoS₂ modified with other functional groups are also discussed.     

Alumina Region of the Lithium Aluminosilicate System: A New Window for Temperature Ultrastable Materials Design

Revisiting classic phase diagrams and chemical phase relations in the solid state of a very well‐studied oxide system, such as the lithium aluminosilicate (LAS) system, can open a new window for the design of new advanced materials with improved properties. Crystal chemistry and phase equilibria are used to demonstrate the ability to design materials with particular desired properties in the alumina‐rich corner of the LAS phase diagram. The experimental results demonstrate the alumina and β‐eucryptite solid‐state compatibility.     

[2.2]Paracyclophane as a Target of the Organic Solid State: Emergent Properties via Supramolecular Construction

In this account, we review the synthesis of [2.2]paracyclophanes in the organic solid state. Reactions in crystalline solids provide a means to obtain molecules with high degrees of stereocontrol that can also be unattainable in solution. We show that [2.2]paracyclophanes form in the solid state stereospecifically and in quantitative yield via intermolecular [2+2] double photodimerization reactions. The double cycloaddition that affords a paracyclophane in the solid state does not readily occur in solution. Small molecules in the form of hydrogen-bond-donor templates can provide access to [2.2]paracyclophanes in a solid by design. A [2.2]paracyclophane obtained using a hydrogen-bond template is shown to exhibit attractive optical properties and has been employed as a building block of a metal-organic framework (MOF).     

Sodium/Fluorapatite as a New Solid Support for the Synthesis of α,β-Unsaturated Arylsulfones

The fluorapatite, both alone and doped with sodium nitrate, is a new basic catalyst for synthesis of α,β-unsaturated arylsulfones. Activation by water and benzyltriethylammonium chloride has also been investigated. When using an ammonium salt, fluorapatite modified with sodium nitrate is an excellent solid support for synthesis of α,β-unsaturated arylsulfones, leading to excellent yields in a few minutes.     

Effect of Hydrogen Reduction of Silver Ions on the Performance and Structure of New Solid Polymer Electrolyte PEI/Pebax2533/AgBF4 Composite Membranes

In this paper, the effect of hydrogen reduction of silver ions on the performance and structure of new solid polymer electrolyte polyetherimide (PEI)/Pebax2533 (Polynylon12/tetramethylene oxide block copolymer, PA12-PTMO)/AgBF₄ composite membranes is investigated. For PEI/Pebax2533/AgBF₄ composite membranes prepared with different AgBF₄ concentration, the permeances of propylene and ethylene increase with the increase of AgBF₄ concentration due to the carrier-facilitated transport, resulting in a high selectivity. But for propylene/propane mixture, the mixed-gas selectivity is lower than its ideal selectivity. The hydrogen reduction strongly influences the membrane performance, which causes the decrease of propylene permeance and the increase of propane permeance. With the increase of hydrogen reduction time, the membranes show a clearly color change from white to brown, yielding a great selectivity loss. The data of X-ray diffraction and FT-IR prove that silver ions are reduced to Ag⁰ after hydrogen reduction, and aggregated on the surface of PEI/Pebax2533/AgBF₄ composite membranes.     

固体超强酸/沸石分子筛催化合成尼泊金酯

用固体超强酸 Ti O2 / SO- 24 -沸石分子筛催化合成尼泊金酯 ,对催化剂的制备条件和尼泊金丙酯的合成条件进行了研究。在最佳反应条件下 ,尼泊金丙酯的产率为93.5 %。实验还表明 ,此催化剂与单组分固体超强酸 Ti O2 / SO- 24 相比 ,具有成本较低的优点 ,且具有重复使用性 ,是合成尼泊金酯的良好催化剂 ,具有较好的应用前景。