2-氨基嘧啶的生产方法

2-氨基嘧啶的生产方法,属于药物中间体的制备技术领域,包括以下工艺步骤:四烷氧基缩丙二醛与胍盐在极性溶剂中以强酸型离子交换树脂为催化剂进行环合反应,上述反应结束后,对反应混合物进行中和、减压蒸馏制得2-氨基嘧啶。所述的强酸型离子交换树脂为磺酸型离子交换树脂、硫酸型     

棉籽油环氧化反应的研究

以聚苯乙烯磺酸型强酸性离子交换树脂为催化剂，用棉籽油为原料，采用乙酸—过氧化氢—步法合成环氧棉籽油增塑剂。观察了反应温度，离子交换树脂、乙酸和过氧化氢用量对环氧化反应的影响。实验结果表明，使用少量离子交换树脂催化剂和低浓度过氧化氢水溶液，在适当条件下，棉籽油经环氧化反应可以得到环氧值近于６．０的产物。并且，离子交换树脂催化剂经反应使用后结构和催化活性仍未有明显变化。     

均匀设计在负载型酯化催化剂制备中的应用

:以离子交换树脂为载体 ,用均匀设计方法考查了负载型酯化催化剂制备中负载金属盐用量 ,负载温度 ,负载时间和载体粒度等因素对催化剂活性的影响。获得的回归方程能较好地反映各因素与催化剂活性的关系。在优化的实验条件下制备的负载型催化剂 ,对乙酸和乙醇的酯化反应具有较高的催化活性。在用量为反应体系中醋酸量的 5%时 ,反应 1 h,酯的转化率达 36.56%。比没有进行负载处理的离子交换树脂 ,在同样的条件下酯的转化率提高 1 7.32个百分点。     

均匀设计在负载型酯化催化剂制备中的应用

以离子交换树脂为载体,用均匀设计方法考查了负载型酯化催化剂制备中负载金属盐用量,负载温度,负载时间和载体粒度等因素对催化剂活性的影响。获得的回归方程能较好的反映各因素与催化剂活笥的关系在优化的实验条件下制备的负载型催化剂,对乙酸和乙醇的酯化反应具有较高的催化活性。在用量为反应体系中醋酸量的５％时,反应１h,酯的转化率达 ３６．５６％。比没有进行负载处理的离子交换树脂,在同样的条件下酯的转化率提高１７     

离子交换树脂催化酯化研究进展

与传统的无机催化剂相比,离子交换树脂表现出良好的催化性能并且能回收再利用。本文简单介绍了离子交换树脂的种类,重点介绍了离子交换树催化剂在酯化反应中的应用进展。     

离子交换树脂催化剂

本世纪初,人们开始使用无机离子交换树脂——天然泡沸石作为催化剂载体,用于石油炼制工业。1935年,人工首次合成酚-醛型的有机离子交换树脂,四十年代以合成离子交换树脂为催化剂(以下称树脂催化剂)开始用于有机合成反应,从此,催化剂的一支新的生力军——树脂催化剂活跃在有机反应的许多重要领域,几乎一切普通无机酸、碱催化反应均可用阳、阴树脂催化剂来代替。     

离子交换树脂非均相催化乙酰化合成乙酰甲胺磷

研究了在间易搅拌釜中以阳离子交换树脂为催化剂，由甲胺磷催化乙酰化合成乙酰甲胺磷。分别考察了不同类型离子交换树脂的催化乙酰化作用。并且研究了搅拌速度，催化剂用量以及反应温度对乙酰化反应的影响。研究结果表明，以NKC9型离子交换树脂在333.15K温度下具有最好的催化乙酰化作用。     

合成肉桂酸正丁酯的催化剂研究

综述了离子交换树脂，TiSiW12O40/TiO2，硫酸铁铵，杂多酸，氯化铁，聚氯乙烯三氯化铁等几种不同催化剂催化合成肉桂酸正丁酯的实验结果。实验表明：离子交换树脂，TiSiW12O40/TiO2，杂多酸3种催化剂对肉桂酸正丁酯的合成反应具有良好的催化活性，具有实际应用价值。     

酯交换合成碳酸二甲酯催化剂研究进展

综述了近年来国内外碳酸乙烯酯或碳酸丙烯酯与甲醇酯交换合成碳酸二甲酯催化剂的研究进展，重点对金属氧化物催化剂、离子交换树脂和负载型催化剂等多相催化剂的制备和催化性能作了介绍。金属氧化物催化剂在使用过程中可能发生化学变化，催化寿命较短；离子交换树脂对热稳定性较差，不能在高温下长期使用；负载型催化剂活性组分的流失有待解决。尽管存在这些不足，但多相催化剂分离简单，容易实现反应 分离一体化，是今后研究开发的主要方向。     

烯酸加成酯化反应催化剂研究进展

烯烃与羧酸在催化剂作用下进行加成反应生成羧酸酯,这一反应属于原子经济反应,越来越受到研究者的关注。综述21世纪以来烯烃与羧酸加成酯化反应催化剂的研究进展,包括磺酸类催化剂、离子交换树脂催化剂、杂多酸化合物催化剂、离子液体催化剂、沸石分子筛催化剂和过渡金属化合物催化剂等,对各类催化剂活性进行比较,并展望烯酸加成酯化反应催化剂的研究方向。     

树脂催化草酸二乙酯水解动力学

针对Amberlyst-15树脂为催化剂的草酸二乙酯水解过程进行了研究,考察了催化剂用量、水酯比及温度对反应的影响。结果表明Amberlyst-15的加入能明显提高水解速率。草酸二乙酯水解反应为连串反应,草酸单乙酯为中间产物。基于树脂催化反应特点提出了包含离子交换树脂催化作用和水解产生的草酸的催化作用在内的动力学模型。通过实验数据的回归获得动力学参数,模型计算与实验数据的平均相对偏差<0.06,表明该模型适用于草酸二乙酯树脂催化水解动力学规律的描述。     

环氧有机硅油改性丙烯酸树脂的合成及性能

以偶氮二异丁腈为引发剂,通过丙烯酰氧基硅油与丙烯酸酯类单体的自由基共聚合反应,同时环氧828与丙烯酸共聚侧链羧基进行开环反应,合成以乙醇为主要溶剂的单相均匀牛顿型环氧有机硅油改性丙烯酸树脂。并对树脂涂膜的稳定性及硬度、耐水煮性,附着力等性能进行了研究。得到的树脂具有良好的热储稳定性,颜料广泛润湿性。环氧有机硅油改性丙烯酸树脂涂膜具有光泽高、硬度好、丰满度高、玻璃附着力强、耐水煮性好与透明性高等优异性能,适用于高档玻璃烤漆。     

强酸性阳离子交换树脂催化合成乙酸异丙烯酯

以乙烯酮和丙酮为原料,用强酸性离子交换树脂代替浓硫酸作为催化剂,直接酯化合成乙酰丙酮的中间体乙酸异丙烯酯。研究了催化剂种类、催化剂用量、催化剂重复使用次数和反应时间对反应的影响。实验结果表明,D072离子交换树脂催化效果较佳。最佳工艺条件为:反应温度57~70℃,反应时间8 h,催化剂用量5%(以丙酮质量为基准),在此条件下,酯收率可达45%。采用的催化剂不经处理重复使用4次,其催化活性基本与初始活性持平,显示了较好的稳定性。同时具有价廉易得、催化活性好、不腐蚀设备和无环境污染等优点。     

Catalysis with Metal Cation-Exchanged Resins

There have been a paucity of reports dealing with catalytic reactions involving metal or metal cations incorporated into ion-exchange resins. It is the objective of this review to summarize these reactions and to discuss in detail one such resin, a perfluorinated Exchange polymer, PFIEP. here survey two resin types, polystyrene sulfonic acid (PSSA) and PFIEP or Nafion [11. Acid catalysis by ion-exchange resins, in particular PSSA, has briefly been reviewed by Sherrington.     

Comparison between two commercial uranium resins and a uranyl sulphate imprinted resin based on self-assembling MIT

In recent years, resins prepared via molecular imprinting technology have received considerable attention owing to their recognition and selective adsorption. This paper deals with the comparative investigation between a uranyl sulphate imprinted ion-exchange based on self-assembling molecular imprinting technology and two kinds of commercial uranium resins (the medium pore resin D263 and strong base resin 201 × 7). The studies were focused on their kinetics performance, adaptability toward pH, and performance of saturation and elution in laboratory-scale column. The results show that the imprinted ion exchange resin has the fast kinetics, high adaptability toward pH, and good adsorption and elution performance.     

有机硅改性丙烯酸树脂性能研究

通过丙烯酸树脂与有机硅中间体接枝反应,制备了耐化学性好、附着力强、耐候性优异、透水气性好的有机硅改性丙烯酸树脂,研究了配方和工艺对其性能的影响、     

Modified DIX model for ion-exchange equilibrium of L-phenylalanine on a strong cation-exchange resin☆

L-phenylalanine, one of the nine essential amino acids for the human body, is extensively used as an ingredient in food, pharmaceutical and nutrition industries. A suitable equilibrium model is required for purification of L-phenylalanine based on ion-exchange chromatography. In this work, the equilibrium uptake of L-phenylalanine on a strong acid-cation exchanger SH11 was investigated experimental y and theoretical y. A modified Donnan ion-exchange (DIX) model, which takes the activity into account, was established to predict the uptake of L-phenyl-alanine at various solution pH values. The model parameters including selectivity and mean activity coefficient in the resin phase are presented. The modified DIX model is in good agreement with the experimental data. The optimum operating pH value of 2.0, with the highest L-phenylalanine uptake on the resin, is predicted by the model. This basic information combined with the general mass transfer model wil lay the foundation for the prediction of dynamic behavior of fixed bed separation process.     

半连续式密实移动床离子交换装置吸附K+特性

在一套半连续式密实移动床离子交换装置上,以001×7强酸型阳离子交换树脂作为吸附剂,研究了钾离子的吸附特性。结果显示,密实移动床离子交换柱全柱的钾离子吸附率能够达到99.71％及以上,排放树脂的吸附饱和度达90.76％;同一套装置,在进料条件和进出料控制要求相同的情况下,采用半连续式密实移动床操作的吸附时间为固定床操作的3/8。研究结果为密实移动床的操作和结构优化提供了参考依据,并表明该装置在离子交换领域具有广阔的应用前景。     

Synthesis and characterization of novel ion-exchange resin based on polyimide containing 8-hydroxyquinoline as a pendent groups

Novel ion-exchange resin (PBMDDMCMHQ polyimide) having 8-hydroxyuinoline as a pendent groups was prepared using phenylenebismaleimide-diamine polyimide (PBMDDM) and 5-chloromethyl-8-hydroxyquinoline hydrochloride (CMHQ). Phenylenebismaleimide-diamine polyimide (PBMDDM) was prepared by Michael addition reaction of 1,3-phenylenebismaleimide (PBM) and 4,4’-diaminodiphenyl methane (DDM). The resulting ion-exchange resin was characterized by spectral techniques. Polymeric metal chelates of ion-exchange resin were also prepared using transition metal ions Zn(II), Cu(II), Ni(II), Co(II) and Mn(II), and were duly characterized. Ion-exchange properties of ion-exchange resin (PBMDDMCMHQ) for Fe(III), Zn(II), Ni(II) and Cu(II) metal ions were also studied by batch-equilibration method. The produced ion-exchange resin (PBMDDMCMHQ) has thermal stability up to 220°C and can be used over a wide pH range. It has good metal up take capacity at varying pH range and can be recycled.     

Removal of Chlorophenols from Aqueous Solution by Anion-Exchange Resins

Abstract

The effects of pH value and chloride ion concentration on the removal of chlorophenols from aqueous solutions by Purolite A-510 resin [macroreticular polystyrene-divinylbenzene resin with R(CH₃)₂(C₂H₄OH)N⁺ group] are discussed by the species distributions of chlorophenols. Those chlorophenols include phenol, 2-chlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. The investigations showed that the chlorophenols could be removed effectively at alkaline conditions where the ion-exchange reaction was dominant. Also, the removal of chlorophenols increased with the number of chlorine atoms on the chlorophenols. The removal of chlorophenols via the ion-exchange reaction was hindered by the presence of chloride ions. The effect of chloride ions, however, was diminished in acidic solutions where the adsorption reaction was dominant. The proposed equilibrium model, which considers both adsorption and ion-exchange reactions, adequately describes the sorption behavior of chlorophenols. The partition constants of the protonated chlorophenols can be estimated from the octanol/water partition coefficients of the phenolic compounds.