高纯度对苯二甲酸的生产技术进展

简述了当前高纯度对苯二甲酸主要的生产方法,包括对二甲苯液相氧化与加氢精制法、对二甲苯精密氧化法以及对苯二甲酸二甲酯水解法等,比较了各种生产方法的优缺点;从催化剂的研制、溶剂的选择、反应器的改造、新生产路线的开发等方面总结了近年来对苯二甲酸合成技术的研究进展,突出了对二甲苯液相氧化与加氢精制法在这一生产和研究领域的重要地位,提出了今后一段时期的技术开发动向。     

Asymmetric synthesis of 3β-acetoxy-17,17-ethylendioxy-15β,16β-methylene-5-androsten-7β-ol

3β-acetoxy-17,17-ethylendioxy-15β,16β-methylene-5-androsten-7β-ol( Ⅰ ) was prepared by 3 steps from 3β-acetoxy-15β,16β-methylene-5-androsten-17-one ( Ⅱ ) with overall yield of 52.7%. Thus, interaction of ethylene glycol and material ( Ⅱ ) gave 3β-acetoxy- 17,17-ethylendioxy-15β,16β-methylene-5-androsten ( Ⅲ ) which was subsequently oxidated and stereoselectively reduced to produce compound( Ⅰ ). The normal influencing factors, such as the types of oxidants and reductives, the mole ratio of reactants, the reaction temperature, and the addition ways of reactants, in oxidation and reduction were discussed. The results show that the oxidation rate order is CrO3-C5 H5 N (1: 1, mole fraction)＞CrO3-C5H5 N(1: 2)＞ (C5H5NH)2 Cr2O7 in terms of the oxidant, the yield of the oxidation becomes higher with increasing the oxidant stoichiometry and raising the reaction temperature. And the optimum condition is that the reaction temperature is at 30 ℃, and n(Ⅲ)/n(CrO3-C5H5N(1: 2))=1: 20. The yield of the -7β alcohol order with Li[Al(OC(CH3)3)3H] (e. G. 78. 6%) is more than that with NaBH4 (e. G. 14. 5%) in terms of the reductive agent and the reduction rate decreases in the course of reaction. The compound (Ⅰ) is characterized by 1R and MS.     

用升压器提高Ziegler-Natta催化剂活性

在ziegler-Natta催化剂催化聚合过程中,溶剂和单体中的溶解氧主要来源于系统中的保压氮气,溶解氧的存在降低了催化剂的催化活性。以镍系催化剂为例,考察了溶解氧对丁二烯聚合系统的影响,并考察了使用升压器后的作用效果。结果表明,用升压器代替氮气保压,是一种很有效的消除系统溶解氧的方法之一,可大幅度提高催化剂的催化活性。     

卤-锑协同阻燃机理研究进展

详细论述了卤－锑阻燃协同体系的阻燃机同机理，以及卤－锑阻燃机理方面的研究新进展。     

氯—锑阻燃体系的协效行为

介绍了卤－锑阻燃协效体系的阻燃协效机理，综述了卤－锑阻燃协效机理方面的研究新进展。     

氯氧化锑与三氧化二锑的阻燃应用性能

氯氧化锑（SbOCl,Sb4O5Cl2）的阻燃性能优异,为推广其工业应用,研究了氯氧化锑在不同材料中的阻燃性能及相关性能,并与常用的Sb2O3性能进行了比较。在软质PVC,PE,PP和ABS等高聚物中,与含Cl和Br的化合物配合使用,SbOCl和Sb4O5Cl2的协同阻燃性能都优于超细Sb2O3,且SbOCl的阻燃性能最优。添加Sb4O5Cl2时,材料的发烟量比添加超细Sb2O3的少。研究结果表明：与添加Sb2O3的PVC薄膜透光率相比,添加SbOCl的PVC薄膜透光率要高1．0－1．2倍,添加Sb4O5Cl2的要高出0．3－0．5倍;SbOCl和Sb4O5Cl2晶体的拆光率分别为1．69和1．74,表明阻燃剂的折光率与高聚物的折光率越接近,其对高聚物的透光率的影响就越小;用SbOCl和Sb4O5Cl2代替超细Sb2O3后,70℃绝缘阻燃PVC电缆料制品的各项指标均符合国家标准GB8815－88,表明SbOCl和Sb4O5Cl2可以替代超细Sb2O3作为该PVC电缆料中的阻燃添加剂。     

煤的微生物转化

煤的微生物转化是煤炭综合利用研究中的新领域.本文从微生物溶煤试验方式、溶煤微生物、可被微生物溶解的煤、微生物溶煤产物分析、微生物溶煤活性物及溶煤机理、微生物溶煤产物的应用等方面详细地探讨了煤的微生物转化研究的现状.指出寻求高效菌种、开发溶煤新产品及探索溶煤产物的新用途将是今后煤的微生物转化的主要研究方向.     

直接由工业Sb_4O_5Cl_2合成SbOCl阻燃剂

以湿法锑白工艺中的中间产物Sb_4O_5Cl_2为原料,在常温(25℃左右)、低酸([H+]<3.1 mol/L)的温和条件下,合成了高纯度、高白度的微细Sb℃l阻燃剂. 最佳合成条件为：搅拌速度大于40 s(1,反应时间大于16 h, CSb3+≥290 g/L,这时固体Sb_4O_5Cl_2的转化率达100%,产物平均粒度5.90 μm,颗粒为立方晶体. 测试表明,产物Sb℃l的阻燃协效性能优于超细Sb_2O_3,且能降低色料用量, 提高高聚物的透明度.     

精对苯二甲酸生产技术的进展

针对精对苯二甲酸主要的工业生产技术,综述了以对二甲苯为原料的液相氧化法与加氢精制法等工艺过程及近年来精对苯二甲酸合成工艺技术的研究进展。指出了以高温水作溶剂及无卤催化剂体系的绿色化学工业是今后一段时期生产精对苯二甲酸的技术动向。     

Preparation of p-menthane hydroperoxide from p-menthane in presence of metalloporphyrins

The aerobic oxidation of p-menthane to p-menthane hydroperoxide (PMHP) in the presence of metalloporphyrins was investigated in an intermittent mode under an atmospheric pressure of air. Several important reaction parameters, such as the structure of metalloporphyrin, the air flow rate, and the temperature, were studied. The preliminary mechanism of the aerobic oxidation of p-menthane catalyzed by metalloporphyrins was also discussed. The results show that the reaction is greatly accelerated by the addition of metalloporphyrins at very low concentration, in terms of both the yield and formation rate of PMHP, and the high selectivity of PMHP is maintained during the reaction. Temperature of 120 ℃ and reaction time of around 5 h are the optimal conditions for the best result in the presence of 0.06 mmol/L monomanganeseporphyrins ((p-Cl)TPPMnCl). Furthermore, the yield of PMHP is increased remarkably when the reaction is carried out under programmed temperature compared with the constant temperature. When the reaction is catalyzed by 0.06 mmol/L((p-Cl)TPPMnCl) at the air flow rate of 600 mL/min and 120 ℃ for 4 h, and then the temperature is reduced to 110 ℃, for another 4 h, the yield of PMHP reaches 24.3%, which is higher than that of the reaction at a constant temperature of 120 ℃ or 110 ℃ for 8 h.