提高PMMA塑料光纤芯材耐热性的方法

介绍了提高以聚甲基丙烯酸甲酯(PMM A)为芯材的塑料光纤的耐热性的方法。     

油价暴涨，催生脂肪酸甲酯磺酸盐（MES）走向市场

介绍脂肪酸甲酯磺酸盐(MES)的可生物降解、绿色环保以及良好的洗涤性等优点,同时概述了我国的MES生产企业现状。阐述了当前MES的生产技术难点,及国内外的生产技术现状。2005年,国际原油价格暴涨,催生以棕榈油为原料的MES走向市场。     

Enantiomers of methyl substituted analogs of (Z)-5-decenyl acetate as probes for the chirality and complementarity of its receptor inAgrotis segetum 1: Synthesis and structure-activity relationships

The enantiomers of analogs of (Z)-5-decenyl acetate, a pheromone component ofAgrotis segetum, substituted by a methyl group in the 2, 3, 4, 7, and 8 positions and dimethyl substituted in the 4,7 positions, have been synthesized and studied by an electrophysiological single-cell technique and by molecular mechanics calculations. The results demonstrate that the electrophysiological activity as well as the ability of the (Z)-5-decenyl acetate receptor to differentiate between enantiomers depends on the position of the methyl substituent. For analogs methyl substituted in the 2, 4, or 8 position, no differences in the activities of the enantiomers could be observed. In contrast, the enantiomers of the 3- and 7-methyl analogs display a significant difference in the activities, theR-enantiomers being more active than theS-enantiomers. From an analysis of the structure-activity results of the enantiomers of the 4,7-dimethyl-substituted analogs, the chiral sense of the alkylchain of the natural pheromone component on binding to its receptor could be deduced.Schiff., Lepidoptera: Noctuidae.     

Graded‐index plastic optical fiber with high mechanical properties enabling easy network installations. I

A doped poly(methyl methacrylate) (PMMA)–based graded‐index plastic optical fiber (GI POF) with high mechanical strength is reported for the first time. Although the POF is generally believed to have a good mechanical flexibility even if it has a large‐core diameter, such a high mechanical strength has been provided by making the polymer chains in the POF highly oriented in its axial direction. If such an orientation of polymer chains is eliminated, the POF becomes brittle, which is similar to silica‐based fibers. On the other hand, too high an orientation of the polymer chains induces fiber deformation in a high‐temperature atmosphere resulting from orientation relaxation. This study reports how high mechanical strengths such as the tensile strength and the large elongation are provided to the GI POF. By selecting the optimum heat‐drawing conditions, the GI POF has a mechanical strength comparable to that of the commercially available step index (SI) POF. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 404–409, 2004     

磁性负载纳米TiO_2催化剂的制备与光催化性能

采用溶胶-凝胶法在复合磁性载体上负载纳米二氧化钛膜,得到了易于磁性固液分离的复合光催化剂,运用XRD、BET、SEM等方法表征它的物质性质,并以典型的偶氮染料甲基橙为目标污染物,研究了不同工艺条件下制备的催化剂的光催化剂的活性。结果表明:以钛酸丁酯为原料,采用溶胶-凝胶法在复合载体上负载4次,500℃保温2 h,得到的磁载催化剂活性最高,处理初始浓度为20 mg/L,pH值为7,2 h降解率达到46%,同时此催化剂能够用磁场回收利用。     

脂肪酸甲酯乙氧基化物在洗衣粉中的应用

对脂肪酸甲酯乙氧基化物(MEE)在洗衣粉体系中等量代替AEO9进行了应用研究，在洗衣粉前、后配料工艺中加入不同量的MEE或AEO9情况下，综合考察了熔点、黏度、洗衣粉去污性能。CMEE-8、AEO9熔点分别为25℃、21℃，黏度完全相同，后配料工艺制备的洗衣粉去污力基本相当；前配料工艺中CMEE-8与AEO9在质量分数为1．5％、3％、6％、10％时所配洗衣粉料浆黏度的比值分别为1／3．2、1／4．8、1／5．1、1／1．8，洗衣粉去污力基本相当。研究结果表明：CMEE-8无论在前配料、后配料中均可以代替AEO9。     

3-甲基-4-丁酰氨基-5-氨基苯甲酸甲酯的合成

3-甲基-4-丁酰氨基-5-氨基苯甲酸甲酯是重要的药物中间体。以3-甲基-4-丁酰氨基苯甲酸甲酯为原料，经硝硫混酸硝化、铁粉还原得到目标化合物3-甲基-4-丁酰氨基-5-氨基苯甲酸甲酯，总收率72％。研究了硝硫混酸配比、硝化反应时间、还原反应温度、还原反应时间等因素对产物收率的影响，该工艺具有生产成本低，产品质量稳定，收率高的优点。     

丙烯酸/丙烯酸甲酯共聚物聚合工艺研究及其表征

以丙烯酸(AA)、丙烯酸甲酯(MA)为共聚单体,以过硫酸铵和亚硫酸氢钠为氧化还原体系引发剂,异丙醇为链转移剂,以水为溶剂,采用溶液聚合方法,合成P(AA-MA)共聚物,利用红外光谱对合成的共聚物结构和组成进行表征,研究了各因素对共聚物的特性粘数的影响程度,确定了最佳聚合条件为:单体比例为8∶1,加料时间0.5 h,聚合温度80℃,聚合时间2.5 h,过硫酸铵用量6%,亚硫酸氢钠用量2%,异丙醇100%(以单体质量计)。     

Ketonization of fatty methyl esters over Sn−Ce−Rh−O catalyst

A mixture of methyl esters of fatty acids obtained by transterification of nonerucic rape oil was ketonized. The starting material, diluted with methanol, was converted at atmospheric pressure over a catalyst that contained Sn, Ce, and Rh oxides in a molar ratio of 90:9:1. At a temperature of 385°C ketones were obtained with a total yield of 63% at the 96% conversion of starting material. The reported experiments prove that catalysts other than iron that are active in ketonization of primary alcohols can be successfully used in ketonization of esters of fatty acids. The kind of diluent used plays a crucial role in the conversion.     

Gas chromatographic study on high-temperature thermal degradation products of methyl linoleate hydroperoxides

Chromatographic techniques were used to separate secondary products generated by thermal degradation of methyl linoleate hydroperoxides (MLHP). The MLHP were obtained by oxidation, selected, and concentrated by solid-phase extraction (SPE) and thin-layer chromatography (TLC). The purified MLHP were then thermo-degraded in the gas-chromatographic glass liner and analyzed on-line by gas chromatography-mass spectrometry (GC-MS). The MLHP were also thermodegraded and collected in a short silicic acid-packed column, eluted, separated by TLC, and then analyzed by GC. By considering the elution in TLC, the GC retention times and the GC-MS analyses, it was possible to characterize the mono- and the dioxygenated secondary products, particularly those having a boiling point higher than methyl linoleate. The peaks that corresponded to the mono-oxygenated products (epoxy, hydroxy, and keto) were identified, and, on the basis of their MS spectra, molecular structures were proposed. A specific elution order was suggested for keto derivatives: 9-keto,Δ^10,12- and 13-keto,Δ^9,11-octadecadienoate. The hydroxy derivatives, which show the typical fragmentations of 9-hydroxy,Δ^10,12- and 13-hydroxy,Δ^9,11-octadecadienoate, were also identified. On the other hand, identification of the di-oxygenated compounds was more difficult, and, therefore, it was not possible to indicate each positional isomer; however, their elution order could be epoxy-hydroxy and epoxy-keto derivatives.