卤代烃对乙烯气相聚合催化剂性能的影响

在淤浆聚合反应器中考察了二氯甲烷、三氯甲烷、四氯化碳、1,2-二氯乙烷、1,1,1-三氯乙烷、1,1,2-三氯乙烷、1,1,2,2-四氯乙烷、六氯乙烷和1,1,2-三氯三氟乙烷9种卤代烃促进剂对乙烯气相聚合催化剂催化活性的影响。结果表明,卤代烃促进剂的加入可有效提高催化剂活性,促进剂的最佳加入量与卤代烃的数量、种类、卤代位置以及烷烃的类型有关。     

新型高效催化剂气相聚合制备聚乙烯

综合报道了新型乙烯气相聚合ＭＧ型催化剂的制备及其聚合反应性能。研究了采用浸渍反应法制备含ＴｉＣｌ４／ＭｇＣｌ２／ＺｎＣｌ２／ＳｉＯ２醇／Ａｌ（ｉ－Ｂｕ）３的ＭＧ－４型高效催化剂。在压力１．０ＭＰａ下,乙烯聚合催化效率高达４４５￣８８４ｋｇＰＥ／ｇＴｉ,制得了表观密度≥ｇ／０．３７／ｃｍ＾３、重均颗粒分布（２０￣２００目）≥９７．７％、颗粒状态良好的聚乙烯。用ＤＳＣ、ＳＥＭ、ＷＡＸＤ对聚合产物进行了     

负载茂金属催化剂催化乙烯气相聚合

研究了负载茂金属催化剂(n-BuNeCp)_2ZrCl_2/SiO_2的乙烯气相聚合行为及其催化聚合产品的性能。三乙基铝加入聚合体系后可降低负载茂金属催化剂的初始活性,有利于聚合过程中的温度控制。气相聚合产品聚乙烯的重均分子量为(1 42～2.28)×10~5,相对分子质量分布为2.6～3.1,熔点在135℃以上,结晶度约为60%,聚乙烯产物颗粒形态以球形为主.堆密度大于0.35 g/cm~3。     

铬/钒双金属催化剂催化乙烯气相聚合

在实验室小试气相聚合釜中对铬/钒双金属催化剂进行乙烯聚合评价,考察了不同聚合温度和压力时催化剂的性能,研究了不同条件下催化剂的动力学行为,并将其聚合动力学曲线与用工业铬系催化剂的进行了比较。结果表明:随着聚合温度升高,用铬/钒双金属催化剂制备的聚乙烯的相对分子质量减小,熔体流动速率增大,在所研究聚合温度范围内铬/钒双金属催化剂对温度更敏感;随着聚合压力增大,催化剂活性显著提高,聚乙烯相对分子质量增加;聚合动力学曲线与铬系催化剂不同,聚合反应速率先增大再降低最后逐渐达到平稳。     

Ti—Mg催化剂乙烯气相聚合反应研究

研究了乙烯气相聚合Ｔｉ－Ｍｇ催化剂的聚合性能，常压气相聚合催化效率７～１１ｋｇＰＥ／ｇＴｉ，产物表观密度０．３０～０．３３ｇ／ｍｌ，产物颗粒２０～１２０目重量占８９％～９７％，加压搅拌床气相聚合，催化效率６１～８１ｋｇＰＥ／ｇＴｉ，产物表观密度０．３４～０．３５ｇ／ｍｌ，产物颗粒１０～１２０目重量占９１％～９６％。流化床惭烯／１－丁烯共聚合催化效率１００～１６９ｋｇＰＥ／ｇＴｉ，ＭＩ２．１６＝５．     

乙烯聚合铬系催化剂研究进展

铬系催化剂由于活性高、制备工艺简单,且制得的聚合物产品中含有长支链组分及少量超高分子量组分,日益受到人们的关注。本文从铬系催化剂的发展历程、制备方法、聚合机理及研发现状四个角度对铬系催化剂进行了详细的阐述,并指出了今后我国铬系催化剂的研发方向。     

N催化剂在丙烯聚合反应中的应用Ⅰ.预聚与预络合对N催化剂聚合性能的影响

考察了丙烯预聚、预络合对N催化剂聚合性能的影响，结果表明，预络合有助于提高催化剂的聚合活性以及聚合物的表观密度，提高催化剂的抗杂质干扰能力，预聚除能够提高催化剂的活性外，对提高聚丙烯粉料的表观密度和等规指数，减少聚丙烯颗粒的破碎有显著影响。     

乙烯聚合双功能催化剂概述

乙烯在一个以应器中同时进行齐聚和共聚反应的新工艺,是近年来乙烯聚合研究领域中的热点之一,本文以混合型有机铬／氧化铬催化剂和钛系催化剂为例,介绍了乙烯聚合双功能催化剂的制备方法,技术特点,聚合动力学以及所合成树脂的性能等,综述了该研究领域的一些新进展,并对两种不同类型的双功能催化进行了简单评述。     

气相法全密度聚乙烯高效催化剂的研究

主要讲述了一种结构式为[(MgBuCl)_p,(MgCl(?))](?)[Ti(OBu)xCl_y]_b(THF)_c[(C_eH_(?)_2AlCl]_d的齐格勒-纳塔型催化剂的制备方法.该催化剂具有活性高、共聚能力强、氢调敏感的特性,并且在气相聚合反应过程中放热均匀、操作稳定,适合在我国引进的大型气相流化床工艺装置上使用.     

环流流化床反应器中乙烯气相聚合反应研究

研究开发了１种新型的用于乙烯气相聚合反应的环流流化床反应器。通过对工业Ａ催化剂和实验室自制的ＱＣＰ－０１催化剂的乙烯气相聚合反应评价及聚合物产品的颗粒形态等方面的研究,认为环流流化床反应器具有聚合反应平稳、催化剂的聚合活性高、产品粒径分布均匀等特点,是１种具有良好应用前景的新型反应器。     

气相法PE催化剂技术进展及研究设想

就国内外气相法ＰＥ催化剂的研究和技术进展进行综述，并对各种ＰＥ催化剂的制备和性能加以简要介绍，对齐鲁石油化工公司ＰＥ中试装置今后的研究工作提出的设想。     

Ziegler催化剂铝／钛比对乙烯聚合反应的影响

按照乙烯聚合反应机理,论述了Ziegler催化剂铝/钛比降低,对乙烯聚合反应及产品性能的影响,并对所得结果进行了讨论。     

气相法乙烯聚合铬系催化剂的性能研究

在小试及中试实验中,将ＱＣＰ－０１气相法铬系聚乙烯催化剂与工业Ｇ催化剂进行聚合活性及产物性能的对比,结果表明,改进后的ＱＣＰ－０１催化剂的催化均聚活性、共聚性能及聚合产物的主要性能均与Ｇ催化剂相当。     

Polymerization of liquid propylene with a fourth‐generation Ziegler–Natta catalyst: Influence of temperature,hydrogen, monomer concentration,and prepolymerization method on powder morphology

Liquid propylene was polymerized in a 5‐L autoclave batch reactor using a commercially available TiCl₄/MgCl₂/Al(ethyl)₃/DCPDMS Ziegler–Natta catalyst, with a phthalate ester as internal electron donor. The powders from these polymerizations were characterized using laser diffraction particle size distribution (PSD) analysis, scanning electron microscopy (SEM), and bulk density measurements. These characteristics were analyzed as a function of the process conditions, including hydrogen and monomer concentration, polymerization temperature, and the prepolymerization method. It was shown that polymerization temperature influences the powder morphology to a large extent. At low temperatures, high‐density particles were obtained, showing regular shaped particle surfaces and low porosities. With increasing temperature, the morphology gradually was transferred into a more open structure, with irregular surfaces and poor replication of the shape of the catalyst particle. When using a prepolymerization step at a relatively low temperature, the morphology obtained was determined by this prepolymerization step and was independent from conditions in main polymerization. The morphology obtained was the same as that observed after a full polymerization at temperature. Even when using a short polymerization at an increasing temperature, the morphology was strongly influenced by the initial conditions. The effect of variation in hydrogen concentration supported the conclusion that the initial polymerization rate determines the powder morphology. In the absence of hydrogen, high bulk densities, and regularly shaped particles were obtained, even at high temperatures. With increasing hydrogen concentration, the reaction rates increased rapidly, and with that changed the morphology. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1421–1435, 2003     

Studies on Macro-kinetics of Gas Phase Polymerization of Butadiene with Rare-earth Catalyst

The study of the kinetics of gas phase polymerization of butadiene with heterogeneous catalyst based on neodymium (Nd) was carried out. The effects of reaction temperature, reaction pressure, dispersing medium, and types of catalyst on kinetics of polymerization were investigated. A kinetic model with two kinds of active sites was proposed. The results show that the effects of the reaction temperature and the types of dispersing medium and catalyst on the kinetic performance of polymerization are significant, and that the combined model of first and second order decay of active site of catalyst can be used to describe the phenomena.     

稀土催化剂上丁二烯气相聚合的宏观动力学研究

The study of the kinetics of gas phase polymerization of butadiene with heterogeneous catalyst based on neodymium(Nd) was carried out.The effects of reaction temperature,reaction pressure,dispersing medium, and types of catalyst on kinetics of polymerization were investigated .A kinetic model with two kinds of active sites was proposed.The results show that the effects of the reaction temperature and the types of dispersing medium and catalyst on the kinetic performance of polymerization are significant,and that the combined model of first and second order decay of active site of catalyst can be used to describe the phenomena.     

国外气相法PE工艺进展

介绍国外近几年来在气相法（流化床）ＰＥ工艺技术方面的主要进展,并针对国内的ＰＥ生产技术及科研状况提出设想。