茂金属催化剂在聚烯烃中的应用

1引言聚烯烃树脂是合成树脂中最通用的品种之一．自1953年发现Ziegler－Natta催化剂，并用于聚乙烯（PE），聚丙烯（PP）的工业化生产以来，聚烯烃技术获得迅速的发展，并开发出节能型气相法工艺技术，目前全世界聚乙烯年产量已达200000kt，占聚烯轻树脂总产量的30～40％。聚丙烯达17870kt．另一方面，1980年汉堡大学Kaminsky教授发现单活性中心的茂金属催化剂，mPE及其它一些聚烯烃随之诞生。由于该催化剂可以精密地控制聚合物分子，能够按照用户要求“定制”无视立构，等现立构或间规立构的任何一种结构的聚合物，并且可以生产用op－N…     

茂金属催化剂在功能聚烯烃合成中的应用

新型茂金属催化剂使古老的聚烯烃领域重焕青春。本文主要介绍了茂金属在功能聚烯烃合成中的应用,包括共聚、使用阳离子型茂金属催化剂和活性聚合等方法。     

茂金属催化剂在聚烯烃生产中的应用

茂金属催化剂是一种具有均匀的活性中心、分子裁剪性和结构可控性的新型催化剂，用它催化可制得具有特殊性能的茂金属聚烯烃，本文简要介绍了茂金属催化剂的结构特点及在聚烯烃生产中的应用。     

茂金属催化剂在聚烯烃生产中的应用

茂金属催化剂是一种具有均匀的活性中心、分子裁剪性和结构可控性的新型催化剂,用它催化可制得具有特殊性能的茂金属聚烯烃,本文简要介绍了茂金属催化剂的结构特点及在聚烯烃生产中的应用。     

茂金属催化剂及工业应用

茂金属催化剂是一种具有均匀的活性中心，分子裁剪必和结构可控性的新型催化剂，用它催化制得具有特殊性能的茂金属聚烯烃，本文简要介绍了茂金属催化剂的结构特点及在聚烯烃生产中的应用。     

茂金属聚烯烃弹性体应用研究进展

对茂金属聚烯烃弹性体(POE)进行了全面综述,详细介绍了近10年来POE在热塑性弹性体、交联橡胶和塑料增韧3方面的应用。     

SEBS新型弹性体和茂金属催化剂

概述了新型热塑怀弹性体ＳＥＢＳ的性能,用途以及广阔的需求市场;介绍了传统的生产工艺技术和近年来国外工发的茂金属催化剂新工艺动向;指出了我国应在发展ＳＢＳ生产基础上加大投入力度,开发ＳＥＢＳ工业化技术。     

使用茂金属催化剂制备聚烯烃弹性体的研究

优化了桥联结构的茂金属催化剂在甲基铝氧烷(MAO)活化下合成乙烯-己烯共聚物的溶液聚合工艺参数。详细考察了Al/Zr摩尔比、聚合反应温度和共聚单体用量等聚合条件对催化剂活性以及聚合产物性能的影响。     

茂金属催化剂及其应用

介绍了茂金属催化剂的结构、特点其及在聚烯烃领域的应用。     

茂金属催化剂应用于丙烯的聚合

本文论述茂金属催化剂的结构对丙烯聚合活性以及所形成的聚丙烯的立构规整度等的影响, 讨论丙烯聚合机理, 介绍聚丙烯弹性体的聚合。     

用于茂金属催化剂的载体及其研究进展

概括了近年来茂金属催化剂负载化的研究进展,包括新型载体的研制、载体的负载特性、负载化对催化性能以及聚合产物性能的影响,强调指出,应着重关注催化剂负载后的微观环境及聚合物的相态,以便利于满足茂金属催化剂在现有工业装置中应用的适应性。     

Polymerization of allylbenzene with metallocene catalysts

Summary Homopolymerization of allylbenzene was carried out with various metallocene/methylaluminoxane (MAO) catalysts. Different polymerization behavior was observed depending upon the catalysts empolyed. rac-Et(Ind)₂ZrCl₂ and rac-Me₂Si(Ind)₂ZrCl₂ gave semicrystalline polyallylbenzenes while i-Pr(CpFlu)ZrCl₂ and CpTiCl₃ did not give any polymeric product. The Cp₂ZrCl₂ gave amorphous polyallylbenzene with low molecular weight. The effect of temperature on the polymerization was investigated with a constant Al/Zr ratio. The temperature showing maximum catalyst activity is higher for the ansa metallocene catalysts than Cp₂ZrCl₂ catalyst. The IR and NMR spectra indicated that the polyallylbenzene consisted of allylbenzene repeating unit and no isomerization occurred. Received: 7 December 1998/Revised version: 29 January 1999/Accepted: 9 February 1999     

POE在塑料增韧改性中的应用进展

聚烯烃弹性体(POE)综合性能优异,广泛应用于通用塑料和工程塑料的增韧和抗低温改性中。与传统增韧改性剂相比,POE和功能化的POE在较低含量下就能实现材料的脆—韧转变。综述了POE和功能化SPOE对通用塑料和工程塑料改性的研究概况和应用发展。     

Oligomerisation of 1-pentene with metallocene catalysts

The homo-oligomerisation of 1-pentene in the presence of various bridged and non-bridged metallocenes and methylaluminoxane (MAO) at room temperature and at 60°C, respectively, has been studied. The use of the bridged catalysts rac-[C₂H₄(Ind)₂]ZrCl₂ ( 1 ) and [(CH₃)₂Si(Ind)₂]ZrCl₂ ( 2 ) leads to the formation of isotactic poly(1-pentene). The use of Cp₂ZrCl₂ ( 3 ), Cp₂HfCl₂ ( 4 ) and [(CH₃)₅C₅]₂ZrCl₂ ( 5 ) leads to the formation of atactic poly(1-pentene). The stereoregularity of the isotactic poly(1-pentene) obtained with 1 was higher than that of the poly(1-pentene) synthesised with 2 . The degree of polymerisation was highly dependent on the metallocene catalyst. Oligomers ranging from the dimer of 1-pentene to poly(1-pentene) with a number-average molar mass M_n = 5100 g mol^–1 were formed. The ¹H NMR spectra of the samples were analysed with regard to functional groups and these were attributed to different chain termination processes. A MALDI-TOF spectrum of low-molar-mass poly(1-pentene) could be recorded using dithranol as matrix and adding silver trifluoroacetate to promote ion formation.     

茂金属催化不饱和聚合物加氢研究进展

介绍了茂金属在催化不饱和聚合物加氢的应用、机理、高效催化体系及合成方法的研究进展,重点综述了加氢活性高的茂钛催化体系。指出茂金属是一种很有市场前景的加氢催化剂,多元化降低成本是茂金属催化不饱和聚合物加氢工业突破的关键。     

Polymer-supported metallocene catalysts for gas-phase ethylene polymerization

The use of hydroxylated chloromethylated-styrene/divinylbenzene copolymer as a support for three different catalysts, Cp₂ZrCl₂, [Ind]₂ZrCl₂ and (CH₃)₂Si[Ind]₂ZrCl₂ has been examined for the polymerization of ethylene in gas phase. The gas phase polymerization experiments were performed in a horizontal reactor by using Box-Behnken experimental design [Box and Wilson, 1951] to study the effects of temperature, ethylene partial pressure, and MAO cocatalyst level on polymerization. The measured average catalyst activities were empirically correlated with these three factors. Temperature appears to be the most important factor, which shows a first and second order effect on activity and also interacts with pressure and MAO. The kinetic study shows that these supported catalysts might contain two types of active sites, and the deactivation of sites follows a first order kinetic. This paper is dedicated to Professor Wha Young Lee on the occasion of his retirement from Seoul National University.     

杂多酸催化剂在有机合成中的应用

介绍了杂多酸催化剂在Friedel-Crafts酰基化和烷基化反应、Diels-Alder反应、酯化反应、环缩合反应、重排反应、溴化反应、氧化反应及不对称催化反应等有机合成反应中的应用。展望了该领域未来的研究方向。     

沸石催化剂在甲胺合成中的应用

介绍了有关沸石分子筛的择形改性研究及其在甲胺合成工业中的应用和进展。