四异丁氧基镍酞菁的合成及其溶剂效应

4 异丁氧基邻苯二腈与氯化镍在强有机碱 1 ,8 二氮杂双环 (5 ,4,0 )十一碳烯 7催化下反应 ,合成了四异丁氧基镍酞菁 ,产物经FT -IR、元素分析、UV -Vis吸收光谱和1 H NMR表征了结构 ;并研究了其溶剂效应 ,结果表明 :最大吸收峰波数ν与函数 f(n ,ε)存在一定的线性关系 ,线性相关系数为 0 940 2 ,而Bayliss函数项 (n2 - 1 ) /(2n2 +1 )决定了最大吸收波长 (λmax)的位移变化 ;化合物的λmax在不同溶剂中随聚集程度增加 ,发生一定程度的蓝移     

Preparation of water‐repellent silks by a reaction with octadecenylsuccinic anhydride

Silk fibers and membranes were acylated with octadecenylsuccinic anhydride (ODSA) at 75°C for different times. Swelling [N,N‐dimethylformamide (DMF) and dimethyl sulfoxide (DMSO)] and nonswelling (xylene) solvent media were used for the reaction. Silk membranes that reacted in DMF or DMSO displayed faster reaction kinetics and attained higher weight‐gain values than fibers. The effect of the solvent on the reaction yield was in the following order: DMSO > DMF ? xylene. The Fourier transform infrared spectra of acylated silk samples showed the characteristic absorption bands of the anhydride at 2990, 2852, 1780–1700, and 1170 cm^?1. The intensity of the latter band, which increased linearly with the weight gain, was used as a marker for evaluating the reaction kinetics of the samples acylated in the nonswelling medium. The moisture regain and water retention of silk fibers acylated with ODSA decreased significantly, regardless of the solvent system used. Accordingly, the water repellency increased. Acylation induced an increase in the thermal stability of the silk fibers and membranes. Fine particles adhering to the surfaces of the silk fibers acylated in xylene were detected by scanning electron microscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 324–332, 2003     

Solubility of Si3N4 in Liquid SiO2

The nitrogen solubility in the SiO₂-rich liquid in the metastable binary SiO₂-Si₃N₄ system has been determined by analytical TEM to be 1%–4% of N/(O + N) at 1973–2223 K. Analysis of the near edge structure of the electron energy loss peak indicates that nitrogen is incorporated into the silicate network rather than being present as molecular N₂. A regular solution model with a positive enthalpy of mixing for the liquid was used to match the data for the metastable solubility of N in the presence of crystalline Si₃N₄ and to adjust the computed phase diagram. The solubility of Si₃N₄ in fused SiO₂ is far less than reported in liquid silicates also containing Al, Mg, and/or Y. Apparently, these cations act as modifiers that break anion bridges in the silicate network and, thereby, allow further incorporation of Si₃N₄ without prohibitive amounts of network cross-linking. Finally, indications emerged regarding the diffuse nature of the Si₃N₄-SiO₂ interface that leads to amorphous regions of higher N content.     

Polar and Non-Polar Solvent Permeation Resistance of Blow-Molded Bottles of Polyethylene/Blends of Modified Polyamide and Polyamide 6 Clay Nanocomposite

Investigations on white spirit and acetone permeation resistance of modified polyamide and nylon 6 clay (MPANYC) blends and their corresponding polyethylene/MPANYC bottles were reported in this study. The white spirit and acetone permeation resistance of MPANYC sheets improve consistently with increasing NYC contents present in MPANYC resins after blending nylon 6 clay (NYC) in modified polyamide (MPA) resins. However, the order of barrier improvement of the PE/MPANYC and PE/NYC bottle specimens is not corresponding to the order of barrier improvement of the MPANYC and/or NYC barrier resins added in PE. The blow-molded PE/NYC bottle specimen exhibits similarly worse white spirit and acetone solvent permeation resistance as the PE bottle specimen, wherein no clearly formed NYC laminas but only dispersed NYC droplets or agglomerates were found on the fracture surfaces of the PE/NYC bottles. However, after blending optimum compositions of MPANYC in PE, the PE/MPANYC bottles with demarcated MPANYC laminas exhibit significantly better white spirit and acetone permeation resistance than the PE/MPA bottle, wherein the white spirit and acetone permeation rates of the PE/MPA₈NYC₁ bottle are about 1.3 and 1.4 times slower than those of the PE/MPA bottle, respectively. In order to understand these interesting barrier properties of PE/MPANYC and PE/NYC bottles, rheological, thermal, wide angle X-ray diffraction and morphological properties of the base MPANYC and NYC resins and their corresponding morphology present in the blow-molded bottles were investigated.     

常见塑料溶解性能研究及其混合物的选择性分离

以常见塑料为原料,以有机物为溶剂,研究了塑料在有机溶剂中的溶解性能,提出了选择性分离混合塑料的方案。结果表明,实验所选用的塑料在有机溶剂中的溶解性能和溶解条件不同;可利用塑料与有机溶剂的相容性差别分离混合塑料。     

Fat-simulating and accelerating solvents for polyolefins and MWD of solvent extracts of polyethylenes

Migration kinetics of straight-chain oligomers and antioxidants from several polyolefins at different temperatures into various solvents have been studied by radioactive tracer techniques. Anhydrous ethanol appears to be a well suited food-oil or liquid-fat simulant for extracting different types of migrants from polyolefins. Pure and mixed triglycerides are also good oil or fat simulants, but the triglycerides offer no simpler analytical procedures than the use of oil or fat themselves. n-Octanol may also be considered as a reasonable oil or fat simulant; however, its action depends somewhat on the choice of migrants. The accelerating action of n-heptane over that of oil or simulants is quantitatively demonstrated. The accelerating effects are greater for migration systems with lower diffusion coefficients. The diffusion coefficients for migration into n-heptane are about 20 times greater than the diffusion coefficients into ethanol or oil for otherwise identical migration systems yielding diffusion coefficients of about 10^?7 cm²s^?1 into oil or ethanol. For systems yielding diffusion coefficients into oil or ethanol of about 10^?12 cm²s^?1, the corresponding diffusion coefficients into n-heptane are about 1000 times greater. The molecular weight distributions (MWDs) of the n-heptane and ethanol extracts of polyolefins have been analysed. n-Heptane can not only accelerate the migration of the individual migrant but also remove oligomer species that are slightly soluble or present at low levels in the oil or simulant extracts.     

深共熔溶剂-水混合物同步提取红景天苷和酪醇的响应面优化及其分离回收

以深共熔溶剂-水混合物（LAEG40）作为提取溶剂，红景天苷提取率为主要指标，酪醇提取率为辅助指标，在前期单因素实验的基础上，利用响应面法考察了液料比、提取温度、提取时间三个主要因素对红景天中红景天苷和酪醇同步提取的影响。得到的最佳提取条件为: 液料比12.05:1(mL/g)，提取温度60 ℃，提取时间35 min。在此条件下LAEG40对红景天苷的提取率可达到19.3552?0.6604 mg/g，酪醇提取率可达到1.7211?0.0585 mg/g，远高于传统溶剂水、乙醇对红景天苷和酪醇的提取率。为实现LAEG40提取红景天苷和酪醇的回收，进行了大孔树脂吸附分离的研究。经过一系列优化，获得的最佳吸附分离条件为：选用SP-825树脂装柱，每10g树脂上样30 mL LAEG40提取液，洗脱剂选用80 %乙醇，洗脱体积40 mL，洗脱流速1 mL/min，在此条件下红景天苷和酪醇的回收率分别可达60.47 %和85.07 %。     

Deposition of CoO onto MoO3/Al2O3 hydrodesulfurization catalysts by solvent assisted spreading

Solvent assisted spreading of CoO over monolayer MoO₃/Al₂O₃ catalysts has been studied. CoCO₃ · Co(OH)₂ and CoCO₃ reacted with MoO₃/Al₂O₃ in water slurries. CoO deposition over MoO₃/Al₂O₃ extrudates was followed by EPMA. In the set of eleven MoO₃/Al₂O₃ catalysts, the amount of CoO adsorbed was roughly proportional to the surface area of MoO₃ monolayer. The adsorbed Co species efficiently enhanced the HDS activity.     

氟两相体系及其在有机合成中的应用

简要介绍了氟化学的发展历史,结合绿色化学和绿色合成技术,介绍了氟化学、全氟溶剂、氟两相体系和氟代催化剂的概念,特性,对氟两相体系在有机合成和催化反应中的应用以及研究进展作了综述。     

Radical scavenging activity of canola hull phenolics

Possible use of canola hulls as a source of natural anti-oxidants was explored. Cyclone canola hulls were extracted with methanol (30 to 80%, vol/vol) and acetone (30 to 80%, vol/vol). The free radical-scavenging activity of phenolic extracts so prepared was evaluated using the 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical ion (ABTS^o−), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and chemiluminescence assays. The total content of phenolics in prepared extracts from canola hulls ranged from 15 to 136 mg sinapic acid equivalents per gram of extract. Higher levels of condensed tannins were detected in the acetone extracts than in the corresponding methanolic counterparts. Seventy and 80% (vol/vol) acetone extracts displayed markedly stronger antioxidant activity than any of the other extracts investigated. Statistically significant linear correlations were found between TEAC (Trolox equivalent antioxidant capacity) values (expressed in mM of Trolox equivalents per gram of extract) and total pehnolics, TEAC and total condensed tannins (i.e., determined using the modified vanillin and pronthocyanidin assays), as well as TEAC and protein precipitation activity of phenolic extracts (i.e., measured using the dye-labeled assay). The antioxidant activities of extracts as determined by the ABTS^o− radical ion assay correlated highly with those of the chemiluminescence and DPPH radical assays.