乙烯直接取代氯化合成氯乙烯的研究

综述了氯乙烯生产工艺的研究进展从清洁生产及原子经济性的角度,分析了乙烯直接取代氯化合成氯乙烯的可行性探讨了氯乙烯合成方法的反应机理,以及催化剂及溶剂效应等因素对氯乙烯合成过程的影响,提出了氯乙烯合成的2种新工艺：乙烯直接取代氯化／HC1电解工艺和乙烯直接取代氯化／HC1两段催化氧化工艺。这2种新工艺比目前工业应用的氯乙烯合成工艺流程短、能耗少、生产成本低。评述了各种生产方法的技术经济指标。     

乙炔法合成氯乙烯无汞催化剂的研究进展

综述了国内外新型无汞催化剂的研究进展,探讨了该反应的反应机理,分析了无汞催化剂的失活原因及其再生方法,并展望乙炔法合成氯乙烯催化剂的发展前景。     

乙炔法PVC与乙烯法PVC对比

比较了乙炔法氯乙烯和乙烯法氯乙烯的合成工艺及乙炔法PVC和乙烯法PVC的生产成本、产品质量,分析了两种工艺中产生的"三废",并提出了处理措施.     

聚苯胺的合成与聚合机理研究进展

近年来,聚苯胺因其优良的性能而备受关注,其合成方法与合成机理一直是聚苯胺研究的重要内容之一.本文详细阐述了聚苯胺的化学氧化和电化学合成方法,并对两类合成方法的反应机理进行了综述.     

偏氯乙烯及其聚合物的研究进展及应用

对偏氯乙烯的合成方法进行了综述,并对其聚合物聚偏氯乙烯的合成方法进行了介绍,指出了乳液聚合和悬浮聚合2种聚合方法各自的影响因素.同时对聚偏氯乙烯热稳定性研究进行了介绍,并提出了相应的提高聚偏氯乙烯稳定性的办法.     

甲烷氯化物催化偶联合成氯乙烯单体新技术

简要介绍了几种主要的氯乙烯单体生产工艺,证明了甲烷氯化物催化偶联合成氯乙烯单体新技术的热力学可行性,并在实验室分别以一氯甲烷和二氯甲烷为原料成功合成出氯乙烯单体,最后指出了这一新技术的优势.     

F-T合成反应机理的研究

对F-T合成反应机理的发展过程,应用范围及研究前景进行了系统综述,着重总结了近期提出的机理模型,讨论了各种反应机理的合理性和欠缺处,并分析了链引发,链增长和链终止在反应机理中的作用,列举了支持各反应机理的直接实验事实。     

氯乙烯本体和悬浮聚合机理及动力学

本文系统地总结了氯乙烯本体和悬浮聚台的主要特征、机理和动力学数学模型。详细地评述了Ravey等的氯乙烯聚合相变机理和Talamini等的两相聚合机理以及动力学数学模型的主要代表。     

氯乙烯聚合尾气回收工艺的改进

介绍了一种简单的氯乙烯聚合尾气回收的工艺,将氯乙烯聚合反应后产生的尾气引至氯乙烯合成和精馏工序,通过合成工序的碱洗塔除去影响生产和产品质量的杂质,利用精馏工序的变压吸附装置,吸附回收氯乙烯单体和排放氮气等杂质气体,工艺流程简单,建设投资小,可降低生产成本,实现清洁生产。     

用非汞触媒合成氯乙烯的方法

过去,以乙炔和氯化氢来制备氯乙烯时是将氯化汞吸附在活性炭上作为触媒使用。但在氯乙烯的合成条件下,触媒的挥发性大,寿命短,往往给环境造成污染。而直接用活性炭作为合成氯乙烯的触媒时触媒的活性极低,无实用价值。 下面介绍二种日本近来提出的用非汞触媒合成氯乙烯的方法。 日本电气化学工业株式会社提出     

乙炔法合成氯乙烯用氯化汞催化剂的改良

简单介绍了乙炔法合成氯乙烯的反应原理、工艺流程、操作条件和主要技术指标,以及氯化汞催化剂的规格和制备方法,讨论了氯化汞催化剂的缺陷,总结了在减少汞流失方面对氯化汞催化剂进行改良的进展情况。     

A case study for reactor network synthesis: the vinyl chloride process

A key objective of the integrated reactor network synthesis approach is the development of waste minimizing process flowsheets (Lakshmanan & Biegler, 1995). With increasing environmental concerns in process design, there is a particularly strong need to maximize conversion to product and avoid generation of wasteful byproducts within the reactor network. This also avoids expensive treatment and separation costs downstream in the process. In this study, we present an application of the mixed integer nonlinear programming (MINLP)-based reactor network synthesis strategy developed by Lakshmanan and Biegler (1996a). Here we focus on applying these reactor network synthesis concepts to the vinyl chloride monomer production process. Vinyl chloride is currently produced by a balanced production process from ethylene, chlorine and oxygen with three separate reaction sections: oxychlorination of ethylene; direct chlorination of ethylene; and pyrolysis of ethylene dichloride. The hydrogen chloride produced in the pyrolysis reactor is used completely in the oxychlorination reactor. Byproducts such as chlorinated hydrocarbons and carbon oxides are generated by these reaction sections. These are studied using reaction kinetic models for the three reaction sections. The case study results in optimal reactor networks that improve the conversion of ethylene to vinyl chloride and minimize the formation of byproducts. These results are used to generate an improved flowsheet for the production of vinyl chloride monomer. Moreover, an overall profit maximization, that includes the effect of heat integration, is presented and a set of recommendations that improve the selectivity of vinyl chloride production are outlined. Finally, the optimal reactor structures, overall conversion and annual profit are shown to be only mildly sensitive with respect to small changes in the kinetic parameters.     

氯乙烯合成控制方案的优化

介绍了反应温度、催化剂活性、原料配比、原料纯度、空间流速对氯乙烯合成反应的影响情况;对氯乙烯转化控制方案进行了优化,确定了一组和二组转化器数量分配比例,建立了流量控制模型,并给出了转化器流量调节方法。     

光化副产氯化氢用于合成氯乙烯的探讨

分析和评估了光化副产氯化氢的质量状况,讨论了处理方法,认为通过净化技术可使光化副产氯化氢用于合成氯乙烯的原料。     

乙炔法合成氯乙烯催化剂的研究进展

The synthesis of vinyl chloride is the key of polyvinyl chloride production.There are two main methods for synthesis of vinyl chloride:hydrochlorination of acetylene and oxychlorination of ethylene.The synthesis process of vinyl chloride from acetylene hydrochlorination was introduced in this paper.The research progress in novel low-mercury and mercury-free catalysts at home and abroad was reviewed.The development prospects of the catalyst for synthesis of vinyl chloride from acetylene were also outlined.     

Structural heterogeneities of suspension poly(vinyl chloride). II. Formation of compact glassy particles and the cause of their difficult processing

By modifying the polymerization process of suspension polymerization of vinyl chloride, poly(vinyl chloride) (PVC) samples were prepared containing various amounts of compact glassy particles. It was found that these particles probably arise by a different polymerization mechanism than usual suspension particles, namely, as a result of the nonhomogeneous distribution of initiator in vinyl chloride drops of the polymerization system. It was proved experimentally that the lower heat stability of difficultly processible particles is due to a side reaction between the initiator radical and the PVC polymer chain which causes dehydrochlorination of PVC already under polymerization conditions. This reaction may also explain the yet unknown mechanism of formation of internal double bonds in PVC produced by the radical polymerization of vinyl chloride. In conclusion, the difficult processibility of compact glassy particles is discussed as a consequence of the insufficient drying of these particles in the usual drying process.     

Synthesis of vinyl phenyl acetate and an evaluation of vinyl chloride/vinyl phenyl acetate copolymers

The synthesis of vinyl phenyl acetate, by an ester interchange reaction between phenyl acetic acid and vinyl acetate and utilizing a catalyst, is described. Copolymerization with vinyl chloride, in a suspension system and using a peroxide catalyst, is described on a laboratory and pilot plant scale. Monomer/copolymer compositions, for an initial charge consisting of vinyl chloride/vinyl phenyl acetate (80/20 by weight) are presented over a range of conversions, as an indication of reactivity ratios. Discs, molded from unstabilized copolymers, show very good clarity and color stability, which improve with increased comonomer loading. Some retention of unpolymerized vinyl phenyl acetate monomer occurred, and some increase in softening points resulted following two reprecipitations from acetone into excess methanol. Compound from a 96/4 vinyl chloride/vinyl phenyl acetate copolymer has better color stability than does an equivalent vinyl chloride/vinylidene chloride copolymer compound. The enhanced color and heat stability of the copolymers is attributed to the aromatic character of the comonomer vinyl phenyl acetate.     

An Efficient Bismuth(III) Chloride‐Catalyzed Synthesis of 1,1‐Diarylalkenes via Friedel–Crafts Reaction of Acyl Chloride or Vinyl Chloride with Arenes

In the presence of catalytic amount of bismuth(III) chloride, the reactions of acyl chlorides or vinyl chlorides with arenes afforded 1,1‐diarylalkenes in 25–82 % isolated yield. In the case of the reaction of acyl chlorides with arenes, the procedure includes an initial Friedel–Crafts acylation, subsequent formation of vinyl chlorides and final Friedel–Crafts‐type vinylation of another arene molecule with vinyl chloride. This paper reports the first Lewis acid‐catalyzed cleavage of the C Cl bond of vinyl chloride and its application in the synthesis of multiply subtituted alkenes.     

Mechanism of vinyl chloride polymerization initiated by the AlEt3/diethylenetriamine/CCl4 catalyst system

The mechanism of vinyl chloride polymerization initiated by the catalyst system AlEt₃/diethylenetriamine/CCl₄ has been investigated. The kinetic equations for the vinyl chloride polymerization and the catalyst components interaction reaction support the radical mechanism of the process. A possible mechanism of the initiation is suggested.     

The copolymerization of vinyl chloride with 1-olefins. V. Heat stability of copolymers of vinyl chloride with propene, 1-butene,and 1-pentene

Copolymers of vinyl chloride with propene, 1-butene, and 1-pentene containing 2–15 mol % of 1-olefinic structural units were prepared. The copolymers were dehydrochlorinated at 180°C in an inert atmosphere; the amount of hydrogen chloride split off was determined by continuous potentiometry. The results show that the heat stability of propene, 1-butene, and 1-pentene copolymers containing the same amount of 1-olefinic structural units does not differ significantly. Compared with the homopolymer of vinyl chloride, it is favorably affected by the presence of 1-olefinic structural units in poly(vinyl chloride) (PVC) chains. On the other hand, however, the heat stability of copolymers is impaired by the higher content of structural defects able to initiate the dehydrochlorination reaction. These structural defects, probably represented by chloroallyl groups, are formed in the copolymers during their synthesis. At the beginning of heating, structural defects produce intensive dehydrochlorination and, therefore, copolymers of vinyl chloride with 1-olefins if processed appear to be less thermally stable than does PVC.