邻—(4—乙基苯甲酰基)苯甲酸的研究

本文阐述了通过Friedel-Crafts反应合成邻-(4-乙基苯甲酰基)苯甲酸的方法.研究了影响产物质量的因素,提出了适宜的工艺条件.     

Synthesis and characterisation of copolyesters from poly(ethylene terephthalate) and poly(hexamethylene terephthalate)

Copolyesters containing poly(ethylene terephthalate) and poly(hexamethylene terephthalate) (PHT) were prepared by a melt condensation reaction. The copolymers were characterised by infrared spectroscopy and intrinsic viscosity measurements. The density of the copolyesters decreased with increasing percentage of PHT segments in the backbone. Glass transition temperatures (T_g). melting points (T_m) and crystallisation temperatures (T_c) were determined by differential scanning calorimetry. An increase in the percentage of PHT resulted in decrease in T_g, T_m and T_c. The as-prepared copolyesters were crystalline in nature and no exotherm indicative of cold crystallisation was observed. The relative thermal stability of the polymers was evaluated by dynamic thermogravimetry in a nitrogen atmosphere. An increase in percentage of PHT resulted in a decrease in initial decomposition temperature. The rate of crystallisation of the copolymers was studied by small angle light scattering. An increase in percentage of PHT resulted in an increase in the rate of crystallisation.     

A Convenient Synthesis of Some Coumarin Derivatives Using SnCl2 · 2H2O as Catalyst

Some substituted coumarins have been synthesized by von-Pechmann condensation using SnCl₂ · 2H₂O (10 mol %) as catalyst in ethanolic medium. The reactions are simple, easy in handling and environmentally benign.     

Synthesis and characterization of poly(ethylene aspartate)-metal complexes

Poly(ethylene aspartate) [PEA] was synthesized by the melt condensation of D,L-aspartic acid and ethylene glycol. PEA containing pendent amino and carbonyl groups in its repeating chain was used as the polymeric ligand for complexation with transition metal ions, viz. Co(II), Ni(II), Cu(II), Mn(II), Zn(II), Cd(II), Ca(II), Mg(II), Pb(II) and Hg(II). Complexation was found to be most effective in DMSO. The resulting polyester-metal complexes were solid coloured materials which have been characterized by IR spectroscopy, elemental analysis and magnetic susceptibility measurements. The thermal stability of the polyester-metal complexes was investigated by thermogravimetric analysis (TGA). On the basis of the physico-chemical studies, an oxygen and nitrogen coordinated structure for the polyester-metal complexes is proposed.     

Ultrasound‐activated Knoevenagel condensation of malononitrile with carbonylic compounds catalysed by alkaline‐doped saponites

α,β‐Unsaturated nitriles have been synthesized by Knoevenagel condensation of a carbonylic compound with malononitrile, assisted by sonochemical irradiation. Two alkaline‐promoted clays (Li⁺‐ and Cs⁺‐exchanged saponites) have been employed as catalysts. The influence of the carbonylic compound (benzaldehyde or cyclohexanone) and the use of a solvent on the catalytic activity have been studied. Remarkable increase in the conversion values has been found when the reaction is activated by ultrasound, as compared with the thermal activation. In this green, solvent‐free procedure, α,β‐unsaturated nitriles have been produced in very high yields (97%) when the Cs⁺‐saponite is used as catalyst. Copyright © 2004 Society of Chemical Industry     

2-甲基-3-甲苯基喹唑啉-4-酮盐酸盐的合成研究

以邻氨基苯甲酸为原料，以不同的中间体和不同的脱水剂对2-甲基-3-甲苯基喹唑啉-4-酮的合成进行研究比较，寻找较佳的合成路径。     

Non-contact methods of measuring moisture concentration in external layers of building partitions II—Monitoring of the water vapour condensation on porous surfaces

This paper present the results of the investigation into a potential application of laser radiation for the detection of phase transition processes occurring on the surface layers of porous materials. An attempt was made to discuss in the approximation equations, the relationships between coefficients of the reflected light, the temperature and humidity of the surrounding environment. Laser light reflected from the porous surface carries information about the roughness of the structure. The presence of water microdrop on the surface of the porous material, as a result of condensation and thus a phase transition, leads to the phase displacement of individual rays, which is represented by different images. Therefore, a comprehensive analysis of the reflected light parameters allows a dynamic study of the phase transition phenomena without mechanical intervention.     

蒸发冷凝法中气体压强和蒸发温度对粒子大小的影响

在Ｎ＿２气氛中，用蒸发冷凝法，制备了Ｓｎ细微粒和Ｆｅ及Ｆｅ－４７（ｗｔ）％Ｎｉ合金超细微粒。分别用ＳＥＭ和ＴＥＭ，直接观测粒子大小及其分布。结果表明，平均粒径不是随Ｎ＿２气压强增加单调上升，而是在某一压强Ｐ＿（ｍａｘ）下，出现最大值。随蒸发温度提高，Ｐ＿（ｍａｘ）值迅速增大。粒子大小及其分布与粒子生长机制密切相关。对粒子凝聚生长条件进行了简要讨论。     

Condensation–cyclization reaction for one-pot synthesis of 1,3-thiazolidin-4-one derivatives by poly(p-phenylenediamine) grafted on LDHs as a catalyst with green tool

The three-component reaction between amine, carbonyl compound and thioglycolic acid is now considered as a major strategy for synthesis of 1,3-thiazolidin-4-ones, which consists of the following steps: (i) condensation of aldehyde and amine which results the formation of an imine; (ii) the reaction between thioglycolic acid and the imine which is followed by an intramolecular cyclization reaction, which leads to the formation of the final product. In this way, if no suitable catalyst is employed, the completion of the reaction will not be achieved. Hence, it is of great importance to select an appropriate catalyst so that these compounds can be successfully synthesized. Herein, we employed LDHs@PpPDA as a versatile catalyst for the fabrication of novel derivatives of 1,3-thiazolidin-4-one.     

CO2体积分数对燃煤细颗粒物在水汽环境中凝结长大的影响

为研究燃煤烟气中CO₂体积分数对细颗粒物在水汽环境中凝结长大效果的影响,建立了计算模型并搭建了实验平台,分别从理论计算和实验研究两方面探讨了CO₂体积分数对细颗粒物凝结长大效果的影响。结果表明:随着CO₂体积分数升高,混合烟气的热、质扩散系数均降低,生长管内平均过饱和度增加,细颗粒物长大效果明显;管壁温度越高,随着CO₂体积分数的提高,细颗粒物粒径越大。