合成氯乙烯单体非汞触媒的研究现状及存在问题

目前氯乙烯单体的工业合成方法主要有乙炔氢氯化法和乙烯氧氯化法.在我国,大约70%氯乙烯单体采用乙炔氢氯化法生产.这是由我国的特殊能源结构所决定的.而乙炔氢氯化法工艺路线一直采用剧毒的氯化汞/活性炭为催化剂,该催化剂易挥发流失,对工人健康及当地环境造成了严重的危害.如何消除汞触媒污染,现乙炔氢氯化合成氯乙烯清洁工艺路线,...     

合成氯乙烯单体非汞触媒的研究现状

目前氯乙烯单体的工业合成方法主要有乙炔氢氯化法和乙烯氧氯化法。在我国大约70%的氯乙烯单体采用乙炔氢氯化法生产。这是由我国的特殊能源结构所决定的。而乙炔氢氯化法工艺路线一直采用剧毒的氯化汞/活性炭为催化剂。该催化剂易挥发流失,对工人健康及环境造成了严重的危害。如何消除汞触媒污染,乙炔氢氯化合成氯乙烯清洁工艺路线是氯碱行业函待解决的问题。     

乙炔法合成氯乙烯用无汞触媒研究进展

氯乙烯单体的工业合成方法主要有乙炔氢氯化法和乙烯氧氯化法。我国大约70%氯乙烯单体(VCM)采用乙炔氢氯化法生产。使用新型无汞催化剂替代目前剧毒的氯化汞/活性炭催化剂是该工艺亟待解决的难题。综述了乙炔法合成氯乙烯用无汞触媒的研究进展,探讨了无汞触媒的种类、结构与性能,并展望了今后的发展趋势。     

氯乙烯合成用新型无汞催化剂的研究现状

我国大约70%氯乙烯单体采用乙炔氢氯化法生产,使用新型无汞催化剂替代目前剧毒的氯化汞/活性炭催化剂是该工艺亟待解决的难题。本文概述了国内外氯乙烯合成用催化剂的发展情况,详细介绍了新型氯乙烯合成用无汞催化剂的研究进展,并展望了无汞催化剂的后续发展思路及前景。     

乙炔氢氯化反应用无汞催化剂的研究进展

氯乙烯单体是合成多种化工产品的基础原料,应用领域广泛,乙炔法成为我国合成氯乙烯单体的主流工艺。随着汞资源的日益枯竭和环境的不断恶化,用于乙炔氢氯化反应的无汞催化剂的研究开发方兴未艾。概述近年来国内外乙炔氢氯化反应无汞催化剂的研究进展,探讨催化剂活性组分、载体及制备过程对催化活性的影响,对乙炔法合成氯乙烯用无汞催化剂的发展前景进行展望。     

电石乙炔法合成氯乙烯单体高汞触媒的现状分析

氯乙烯单体(VCM)主要用来合成聚氯乙烯(PVC)。聚氯乙烯是世界五大工程塑料之一,聚氯乙烯在各行各业具有十分广泛的应用。由于能源结构形式和潜在的成本优势,目前,我国氯乙烯单体工业合成工艺主要以电石乙炔法为主。但该法催化剂高汞触媒的使用会带来系列问题,是其发展的瓶颈。本文指出了高汞触媒一系列弊端,对其现状进行了分析,并对电石乙炔法氯乙烯单体合成工艺催化剂的发展趋势进行了展望。     

氯乙烯生产技术的研究开发进展

氯乙烯（VCM）的生产方法主要有电石乙炔法、乙烷法和乙烯氧氯化法，其中乙烯氧氯化法是目前世界上生产VCM最主要的方法，我国的VCM则主要采用电石乙炔法生产工艺路线。介绍了以上3种生产氯乙烯方法的技术进展，指出了其今后的发展方向。     

生物碳材料高效催化乙炔氢氯化反应的研究

乙炔氢氯化反应是煤基氯乙烯合成的重要技术,但一直受汞触媒催化剂毒性问题的困扰。利用竹子下脚料合成的氮掺杂多孔纳米碳催化剂(N@BC),无需添加任何金属元素,可以高效催化乙炔氢氯化合成氯乙烯。研究结果表明,反应温度为200℃,乙炔转化率高达95%,氯乙烯选择性大于98%,反应50 h乙炔转化率保持在90%以上。利用生物质废弃资源合成多孔氮掺杂碳材料的方法,为乙炔氢氯化反应生产氯乙烯的无汞化开辟了一条新思路。     

乙烷氧氯化制氯乙烯

乙烷一步氧氯化制氯乙烯是氯乙烯单体新路线研究的重要动向。据报道,美国鲁姆斯公司开发的“Transcat”法已于1972年2月工业化,并有两个以上的其它公司买了它的专利。有人认为,乙烷一步氧氯化制氯乙烯的工业化是乙烯路线转向乙烷路线的里程碑。所列举的氯乙烯生产成本比较数据为:电石乙炔法,8美分/磅;乙烯氧氯化法,3.2美分/磅;乙烷一步氧氯化法,2美分/磅。经济比较对乙烯路线转向乙烷路线有利。另据报道,鲁姆斯公司根据其开发的从乙烷制氯乙烯的技术,研究出所谓“通用氯化法”,用于处理氯化羟残渣,并制得氯乙烯。     

1,1-二氟-1-氯乙烷合成研究进展

介绍了1,1-二氟-1-氯乙烷(HCFC-142b)的基本性质、用途和合成研究进展,比较了直接氟代法、偏氯乙烯加成氟代法和光氯化法的研究概况和不同方法的优缺点.采用在催化剂存在下,用偏氯乙烯和氟化氢在液相中加成氟化的方法生产HCFC-142b是最具工业前景的合成路线,该工艺路线的关键是氟化催化剂的选择,选择一种助催化剂...     

氯乙烯单体合成催化剂研究进展

氯乙烯（VCM）是应用于高分子化工的重要单体,可以通过乙烯法及乙炔法制得。乙烯氧氯化生产VCM过程中二氯乙烷（EDC）的裂解生成VCM通常需要高温,能耗问题亟待改善。乙炔氢氯化法合成VCM常用氯化汞（HgCl₂）催化剂,其毒性强、挥发性大,对环境和人类健康造成严重污染和危害。替代HgCl₂的贵金属催化剂虽然活性较高,但实现大规模商业化应用还需解决成本昂贵等问题。本文围绕贵金属催化剂、非贵金属催化剂和碳基非金属催化剂在VCM合成方面的最新研究进展,重点介绍了催化剂的活性位点、失活原因以及如何通过合理调控结构来设计催化剂。指出在未来的研究中,探索一种高效、无污染、低成本的催化剂来替代乙炔法HgCl₂催化剂以及开发全新乙烯法催化剂是催化剂设计的重点与难点。     

Reactions of unsaturated fatty alcohols. VII. Polymerization of vinyl ethers catalyzed by stannic and ferric chlorides

Summary Variables affecting the use of stannic chloride as a catalyst for initiating polymerization of conjugated and nonconjugated soybean vinyl ether were studied. Molecular weight of the polymers increased with an increase in catalyst and a decrease in initiation temperature, and it decreased when the amount of moisture in the solvent, the amount of free fatty alcohol in the monomer, or the ratio of solvent to monomer was increased. Aromatic and aliphatic hydrocarbon solvents were superior to halogenated solvents for conducting polymerizations. Similar results were obtained with nonconjugated monomers except that viscosities of the polymers were considerably lower than those of polymers of the same molecular weight obtained from conjugated monomer. To obtain polymers suitable for film-forming studies (4,000–6,000 molecular weight) polymerization is initiated preferably at 25°C. with 3 ml. of anhydrous toluene used per gram of monomer and 4.8 mmoles of stannic chloride per mole of monomer. Monomer purity should be at least 98%. Ferric chloride hexahydrate initiated polymerization at 25°, but polymerization was incomplete, and the polymers had relatively low molecular weights. Presented in part at the fall meeting, American Oil Chemists' Society, Chicago, Ill., Oct. 20–22, 1958. This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

关于氯乙烯转化系统腐蚀的探讨

对转化器腐蚀问题进行了研究,对混合气体冷冻脱水、混合气体预热温度、氯化氯活化触媒和触媒含水等问题进行了探讨,并为解决氯乙烯转化系统腐蚀问题提供了理论依据,从而找出了解决氯乙烯转化系统设备管理腐蚀的原因和防治措施,延长了转化使用寿命,减少设备维修费用,确保氯乙烯单体生产连续稳定的进行。     

Synthesis,Characterization and Application of a Multi-Site Phase Transfer Catalyst in Radical Polymerization of n-Butyl Methacrylate—A Kinetic Study

The multi-site phase transfer catalyzed radical polymerization of n-butyl methacrylate (n-BMA) using newly synthesized and characterized 1,1,2,2-tetramethyl-1-benzyl-2-n-propylethylene-1,2-diammonium bromide chloride (TMBPEDBC) as a multi-site phase transfer catalyst was investigated in an aqueous-organic two-phase system at 60 ± 1°C under nitrogen circumstances. The kinetics and effects of various operating variables (monomer, initiator, catalyst, temperature, acid, and ionic strength) on the rate of polymerization (Rp) were examined in detail. The order with respect to monomer, initiator and multi-site phase transfer catalyst was found to be 0.50. A suitable kinetic reaction scheme has been proposed to account for experimental observations, and its significance is discussed.     

Effects of external Lewis base on the performance of MgCl2 supported catalysts in propylene polymerization

Summary The effects of four different external Lewis bases on propylene polymerization using the MgCl₂-supported TiCl₄ catalyst were studied in the context of the variation of the chemical complexes formed between catalyst, catalyst support and internal Lewis base, and the interactions between complexes and external Lewis base, The internal Lewis base used in this study was dioctyl phthalate. With ethyl benzoate as the external donor no change in activity was observed, but the interaction between ethyl benzoate and MgCl₂·phthaloyl chloride complex resulted in a decrease of isotacticity. Increasing the bulkiness of the external Lewis base hindered the monomer coordination. It was found that the relative amount of the phthaloyl chloride complex to other complexes played an important role in the formation of active sites.     

新型杀生剂DDSC的合成研究

以锡、氯化苄和二甲基十二烷基叔胺为原料,经过两步反应,合成了新型杀生剂二苄基二(二甲基十二烷基胺基)氯化锡(简称DDSC)。通过单因子和正交实验,考察了单体摩尔配比、催化剂用量、反应时间、反应温度等因素对反应的影响。结果表明,适宜的合成条件为:反应时间4~5 h,原料摩尔配比为1∶1∶1,溶剂比为8∶2,催化剂用量为单体质量的2%,低温滴加温度为60℃,高温反应温度为80℃。在此条件下,DDSC的合成总收率可达85%以上。     

Polymerization studies using modified Ziegler-Natta catalysts: 1. Polymerization of vinyl chloride

The polymerization of vinyl chloride by a number of modified Ziegler-Natta catalysts has been investigated. The most effective catalyst system is the soluble system prepared from vanadium oxytrichloride, tri-isobutylaluminium, and tetrahydrofuran. All three components are necessary for the formation of an active catalyst. The kinetics of the polymerization of vinyl chloride by this catalyst system has been examined at 30°C, and the dependence of the overall rate of polymerization on the transition halide concentration, aluminium alkyl concentration, monomer concentration and temperature established. Kinetic and copolymerization studies indicate that the polymerization process is not free radical in nature but is similar to that encountered in more conventional Ziegler-Natta systems.