光学活性的2-苄基-3-羟基丙酸合成

以丙二酸二乙酯为起始原料,经过苄基化、还原、乙酰化保护、氧化、水解等5个步骤,合成了标题化合物.以水为溶剂,对标题化合物与手性1-苯乙胺形成的非对映异构体盐进行手性拆分,得到了(R)-2-苄基-3-羟基丙酸和(S)-2-苄基-3-羟基丙酸.     

3-(S)-巯基-1-(N-对硝基苄氧羰基乙酰亚胺)四氢吡咯的合成

对标题化合物的合成工艺作了改进。以L-羟基脯氨酸为原料,环己酮作催化剂,经脱羧获得的3-(R)-羟基四氢吡咯盐酸盐,与由乙醇和乙腈反应得到的乙氧基乙酰亚胺盐酸盐,经5步反应成功地合成了目标产物,总收率为15.6%,关键中间体及目标化合物经过1HNMR检测,还探讨了标题化合物及其前体的构型转化问题。     

三(2-氨基乙基)胺合成方法的改进

对标题化合物的合成方法进行了改进。首先用三乙醇胺与二氯亚砜在氯仿中反应制备三(2-氯乙基)胺盐酸盐,然后与邻苯二甲酰亚胺钾在二甲基甲酰胺中反应得到标题化合物的盐酸盐,最后在甲醇中用氢氧化钾中和得到标题化合物。总收率65.4%。     

4-(3-异丙基-1,2,4-(口恶)二唑-5-基)哌啶的合成

以异丁腈和盐酸羟胺合成异丁偕胺肟.4-哌啶甲酸经氨基保护、酰化后生成苄基4-(氯甲酰基)哌啶-1-甲酸酯,然后与异丁偕胺肟环合、脱保护合成标题化合物.产物通过LCMS和1HNMR确定其结构.     

N-[4-(间甲基苯甲酰基哌嗪)乙酰基]-N-甲基-3-(1-萘氧基)-3-(2-噻吩基)-丙胺的合成

以N-甲基-3-(1-萘氧基)-3-(2-噻吩基)-丙胺(Duloxetine)为原料,合成了标题化合物.中间体和产物的结构经 ~1HNMR、IR和质谱表征.     

1-(2-甲氧基苯基)哌嗪氢卤酸盐的合成研究

叙述了 1 (2 甲氧基苯基 )哌嗪盐酸盐 (Ⅱ )和氢溴酸盐 (Ⅳ )的合成研究结果。分别以双 (2 氯乙基 )胺盐酸盐 (Ⅰ )及双 (2 溴乙基 )胺氢溴酸盐 (Ⅲ )与邻甲氧基苯胺反应 ,合成了两个标题化合物 (Ⅱ ,Ⅳ ) ,合成收率分别达 5 9%和 80 % ,产品纯度达 98%以上。中间体 (Ⅰ )和 (Ⅲ )用二乙醇胺分别与SOCl2 和 4 0 %HBr反应来制备。还给出了化合物 (Ⅳ )的一釜合成法。     

左旋溴化N-丁基-4-吡啶甲酸薄荷醇酯离子液体合成方法的研究

以异烟酸、(-)-薄荷醇、溴代正丁烷为原料采用两种不同路线合成了标题化合物,并通过IR、1HNMR、13CNMR等手段进行表征。研究发现,酯化后再季铵化获得手性离子液体的方法优于先季铵化后酯化,该方法合成标题化合物总收率75.2%。     

单-(6-乙二胺-6-去氧)-β-环糊精中间体的合成研究

以β-环糊精为原料,在Na OH溶液中制备单-(6-O-对甲基苯磺酰基)-β-环糊精,进一步合成标题化合物,并通过单因素试验研究了合成工艺条件。采用红外光谱和质谱分析对产物进行了结构表征,采用高效液相色谱-蒸发光散射检测对产物进行了纯度分析。标题化合物作为重要的合成中间体,其合成研究对基于6位单取代的衍生物具有较好的参考价值。     

(R)-N-苄基-1-苯乙胺的合成工艺研究

以(R)-1-甲基苄胺为原料,经与苯甲醛缩合和硼氢化钠还原,合成了标题化合物,其结构经 1HNMR、MS等确证,收率达96.4%.     

N-(2-水杨醛缩氨基)苯基-N'-苯基硫脲的合成研究

以邻苯二胺与异硫氰酸苯酯为原料,制备得中间体N-(2-氨基苯基)-N′-苯基硫脲.然后将其与水杨醛反应得到标题化合物.通过元素分析、红外光谱、质谱及核磁共振氢谱对所合成的化合物进行了结构表征.结果表明,该合成方法具有反应条件温和、反应时间短及操作简便等优点.     

Effects of calcination condition on expansion property of MgO-type expansive agent used in cement-based materials

Previous research indicated that the expansion property of MgO-type expansive agent (MEA) depended strongly on the calcining conditions, i.e. kiln temperature and residence time. However, the intrinsic effect of calcination condition on the expansion property of MEA has not been clearly demonstrated. In the present work, the effects of calcination condition on the microstructure, hydration activity, and expansion property of MEA have been investigated, and their correlations are also studied. Results indicate that the microstructure of MEA is the intrinsic factor that controlling its expansion property, which is influenced by the calcination condition. MEA produced under higher temperature and longer residence time has less interior pores, larger crystal size of MgO, and smaller specific surface area, thus resulting in lower hydration activity and slower expansion at early age, but larger “ultimate” expansion at late age. While, a new expansion model of MEA is proposed to explain these results.     

Material and environmental parameter effects on the leaching of cement pastes: Experiments and modelling

Results already published on the leaching of cement pastes have shown that the kinetics depends sensitively on the material and environment. However and because of the variability of the tested materials and leaching protocols, it is difficult to compare these data and quantify the effect of each parameter. In this paper, a large experimental database on the leaching kinetics of cement pastes is built. Four parameters are investigated: type of cement (portland cement, silica fume cement, slag cement, ternary cement with slag and fly ash); water-to-cement ratio (0.5; 0.4; 0.25), temperature (26 °C; 72 °C; 85 °C) and chemical composition of the leaching solution (pure water, mineralised water, ammonium nitrate solution). Firstly, the database is used to calculate the leaching kinetics of the cementitious materials. Secondly, a simplified model predicting the one-dimensional leaching kinetics for other water-to-cement ratios and temperature up to 85 °C is presented.     

Toughening of polypropylene with styrene/ethylene‐butylene/styrene triblock copolymer: Effects of reactive and nonreactive compatibilization

The effects of the compatibilization on the toughening of polypropylene (PP) by melt blending with styrene/ethylene‐butylene/styrene triblock copolymer (SEBS) in a twin‐screw extruder were investigated. The compatibilizers used were an SEBS functionalized with maleic anhydride, a PP functionalized with acrylic acid, and a bifunctional compound, p‐phenylenediamine (PPD). The effects of the compatibilization were evaluated through the mechanical properties and by the determination of the phase morphology of the blends by scanning electron microscopy. Reactive compatibilized blends show up to a 30‐fold increase in impact strength compared to neat PP, which was likely to have been due to the reaction of the bifunctional compound (PPD) with the acid acrylic and maleic anhydride groups, which rendered both morphological and mechanical stability to these blends. The addition of the PPD to the blends significantly changed their phase morphologies, leading to larger dispersed particles' average diameters, probably due to the morphological stabilization at the initial processing steps during extrusion, with the occurrence of the chemical reactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1081–1094, 2003     

Photocatalytic degradation of air pollutants — From modeling to large scale application

Indoor as well as outdoor air quality and their limiting values remain a major problem to our present-day society.This paper addresses the modeling of the decomposition process of nitrogen monoxide (NO) on reactive concrete surfaces under the controlled exposition of a UV source. Within this model the external mass transfer of the pollutant and the internal molecule diffusion-reaction were considered. A first-order kinetics equation is derived with respect to the NO concentration and a site-competitive adsorption between NO/NO₂ and water molecules, resulting in a dependence of the reaction kinetics on the relative humidity. Using the proposed model, a reaction rate constant k and an adsorption equilibrium constant K_d can be derived which describe an active paving stone accurately. Experimental results from a self-developed photoreactor with continuous flow mode were used to validate the proposed kinetic expression. Furthermore, the effect of variations in process conditions such as irradiance and relative humidity on the two constants k and K_d is investigated. All modeling work provides a sound foundation for the translation of this process to real outside conditions. In this regard an upcoming project in a Dutch city is described in brief.     

(SrZrO_3)_(10)(SrTiO_3)_(90)缓冲层对PZT结晶及性能的影响

采用Sol-gel法制备了PbZr0.52Ti0.48O3 (PZT)薄膜,并研究了(SrZrO3)10(SrTiO3)90((SZO)10(STO)90)缓冲层对PZT薄膜结晶和性能的影响.X射线衍射(XRD)结果表明:(SZO)10(STO)90缓冲层对PZT薄膜结晶有取向诱导作用,由(SZO)10(STO)90诱导的PZT薄膜有很强的(111)择优取向,缓冲层将PZT薄膜的取向度α由45.0%提高到了90.1%以上;PZT的(111)择优取向提高了薄膜的电性能,使剩余极化强度Pr从26.8 μC/cm2增大到38.8 μC/cm2.     

硫氰酸锰及其相关衍生物的合成及化学表征

合成了金属有机配合物非线性光学晶体硫氰酸汞锰，及其相关衍生物，二二甲亚砜合硫氰酸汞锰，乙二醇一甲醚合硫氰酸汞锰，二水合二N，N－二甲基乙酰胺合硫氰酸汞锰，二水合二N－甲基－α－吡咯烷酮合硫氰酸汞锰。采用元素分析，红外光谱以及紫外－可见－近红外透央求我谱分析对其进行了化学表征。     

Design and processing of ZnO doped tricalcium phosphate based materials: Influence of β/α polymorph phase assemblage on microstructural evolution

Tricalcium phosphate (TCP) based biomaterials are excellent candidates in hard tissue engineering due to their similarity to the natural bone composition and outstanding properties. The presence of additives such as (Mg²⁺, Zn ²⁺, F⁻, CO₃²⁻ and/or SiO₄⁻) in solid solution in the structure of TCP, affects the stability of its different polymorphs and therefore the properties of TCP based biomaterials. It is known that the incorporation of zinc in TCP in the non-toxic level stimulates bone growth and its mineralization, hence its interest. Nevertheless its effect on phase assemblage and microstructure evolution has not been clearly established. The main purpose of this study was to synthesize TCP and zinc doped monophasic/biphasic α/β-TCP dense biomaterials, by solid-state sintering process, with different ZnO contents and controlled phase proportions and microstructure on the final material. The effect of ZnO content and sintering temperature on phase assemblage, densification and microstructural evolution has been investigated.     

Optimizing multiple qualities in as‐spun polypropylene yarn by neural networks and genetic algorithms

This investigation considers a quantitative procedure for determining the values of critical process parameters in melt spinning to optimize the qualities of denier, tenacity, breaking elongation, and denier variance in as‐spun polypropylene yarn. An orthogonal array in the Taguchi method defines the minimum set of parameter‐level combinations that are experimentally tested. The significant process parameters, namely the third extruder barrel temperature, spinning temperature, metering pump speed, and take‐up velocity, are identified on the basis of the analysis of variance and F test. After a confirmation experiment is conducted to ensure the reproducibility of the experimental results, the back‐propagation neural network establishes a continuous system linking 10 process parameters and four qualities. The technique for order preference by similarity to an ideal solution can be used to obtain a performance measure for assessing multiple qualities. The genetic algorithm attempts to find parameter values for optimizing the quality performance, including the denier, tenacity, breaking elongation, and denier variance. Finally, the experimental results demonstrate that the smallest denier, largest tenacity, smallest breaking elongation, and second smallest denier variance of as‐spun polypropylene yarn can be achieved with the proposed approach in melt spinning. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2532–2541, 2006     

Selective plasma‐induced grafting of polystyrene onto polyolefin blends

Plasma pretreatment has been used to generate reactive radicals and oxygenated groups on polymer surfaces for graft polymerization. The polymer substrates studied were composed of a polypropylene–polyethylene (PP–PE) copolymer, which was predominantly PP, and also contained blended ethylene–propylene rubber (EPR) as either about 15 or about 60 mol %. A pure PP substrate was also studied for comparison. The grafted polymer was polystyrene (PS). Raman microspectroscopic 2‐dimensional mapping was used to elucidate the role of crystallinity and EPR in the plasma treatment and graft polymerization process. It was found that the plasma pretreatment favored the EPR component of the substrate and the graft yield was related to the EPR content. Crystallinity seemed to have a much less significant effect on the grafting reaction. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1643–1652, 2003     

Porosity and specific surface area of Roman cement pastes

Mercury porosimetry, water vapour and nitrogen adsorption were used to follow the hydration of Roman cements — belite cements calcined at low temperature. Generally, unimodal distribution of pore sizes was observed, with the threshold pore width decreasing considerably with increasing curing time. An open porous structure with the threshold pore diameter between 0.2 and 0.8 μm and the specific surface area not exceeding 20 m²/g was produced at early ages when quick growth of the C–A–H phases is observed. The surface area reached up to 120 m²/g and the threshold pore width shifted to around 0.02 μm when the subsequent formation of C–S–H gel filled the larger pores. Both mercury porosimetry and water vapour adsorption were found to be capable of following the progress of hydration of the Roman cements with high reliability at least for a comparative evaluation of historic Roman cement mortars and repair materials used in restoration projects.