共查询到16条相似文献,搜索用时 93 毫秒
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利用XRD和BET测试技术对BCH和NT-1两种工业催化剂进行了物相表征和结构分析,研究了两种催化剂的结构对其催化乙烯淤浆聚合活性的影响。结果表明,BCH催化剂较多的大孔有利于单体的扩散,使得其初始活性较高,随着部分活性中心的被包埋导致中后期活性低于NT-1催化剂。采用NT-1催化剂聚合得到的产品粉末平均粒径大,粒径分布集中,但堆密度略低;产品的力学性能略优于用BCH聚合得到的产品。NT-1催化剂的氢调敏感性和共聚性能优于BCH催化剂。 相似文献
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茂锆金属催化剂催化乙烯聚合研究 总被引:2,自引:0,他引:2
主要考察了含锆的茂金属催化剂中催化乙烯反应条件优化研究,在最优条件下催化聚合反应所得的产物与吉林石化公司聚乙烯厂聚乙烯产品进行分析对比.对茂锆金属催化剂催化乙烯聚合反应条件研究表明,适宜的助催化剂[Al]与主催化剂[Cat]的摩尔比在1 500左右,适宜的主催化剂浓度在1.5×10-4 mol/L左右,最佳聚合温度60℃,此时催化剂的活性可达到106 gPE/(molCat·h).从物理性能、热性能、相对支化度、相对分子质量及其分布分析可知,制备出的负载茂锆金属催化剂在最优反应条件下催化乙烯聚合所得的产物与吉林石化公司聚乙烯产品性质基本一致,符合产品的指标,支链分布均匀,分子量分布更窄.同时对茂锆金属催化剂主、助催化剂催化乙烯聚合的作用和机理进行了探讨. 相似文献
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含Mg—Si复合载体高效催化剂乙烯聚合的研究 总被引:1,自引:0,他引:1
实验采用碱式碳酸镁的热分解产物、MgCl_2、SiO_2分别作载体,和它们组成的复合载体制得的新型乙烯聚合高效催化剂,不但具有高效、长效、良好的分散性等特性,还可显著地降低催化剂和制得产品中的氯含量,这对气相法聚乙烯生产技术开发和提高产品质量有重要意义。研究了催化剂组分、制备方法对乙烯聚合反应的影响,并研究了聚合反应动力学,复合载体的作用,添加剂对催化剂形态、聚合产物形态的作用。 相似文献
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研究了有机硅烷铬酸酯催化剂(简称有机铬催化剂)在乙烯气相均聚合小试中的催化性能和聚合动力学行为。考察了不同种子床制备方法、有机铬催化剂加入量、聚合温度、乙烯与氢气分压比对聚合的影响,并对聚乙烯(PE)进行了结构与性能的分析表征。结果表明:经热活化与化学活化处理后的硅胶表面基本不含羟基,适宜作为种子床使用;有机铬催化剂加入量在100.0~150.0 mg时其活性最高且保持稳定,聚合动力学曲线为快速上升缓慢下降型;聚合温度在80~100℃时有机铬催化剂活性最高且变化不大,但在110℃时下降;随聚合温度升高,PE的重均分子量与数均分子量均降低,且相对分子质量分布明显变窄;H2的加入会显著降低有机铬催化剂活性。 相似文献
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研究组分为TiCl4/MgCl2-SiO2/AlR3的HM型高效催化剂的乙烯聚合,发现催化剂组分SiCl4有促进乙烯聚合的作用,并可以通过调节SiCl4用量控制催化剂Ti含量。ZnCl2有调节分子量的作用。由MgCl2-ZnCl2-SiO2复合载体组成的Ti系催化剂乙烯均聚催化效率为7.1014.0kg/g,聚合产物表观密度为0.23-0.30g.cm^2,20-200目颗粒质量为90%-95%。乙烯与1-丁烯共聚时催化效率大大提高,当1-丁烯的体积分数为10%时,效率高26.0kg/g,共聚产物熔点、结晶度随1-丁烯的体积分数增加而下降,而支化度则随之上升。HM催化剂1m^3反应釜工业试生产的试验结果表明,在05MPa下催化效率达152-241kg/g,聚合产物表观密度为0.33-0.34g/cm^3,20-200目颗粒质量为60.6%-84.3%,小于200目颗粒占1%以下。工业试生产的HM催化剂具有催化效率高、颗粒度均匀、极少细粉、表现密度大等优点,达到或超过了实验室研制的技术指标,具有优良的聚合性能。 相似文献
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Hossein Mahdavi Alireza Badiei Gholam Hossein Zohuri Abbas Rezaee Roghieh Jamjah Saied Ahmadjo 《应用聚合物科学杂志》2007,103(3):1517-1522
An iron‐based catalyst of 2,6‐bis‐[1‐(2‐methylphenylimino)ethyl]pyridine iron dichloride was prepared. The ligand was prepared using 2,6‐diacetylpyridine as the starting chemical under controlled conditions. The preparation procedure was followed using 13C‐NMR, 1H‐NMR, FT‐IR, MS (mass spectroscopy), and elemental analysis methods. The homogeneous polymerization of ethylene was carried out using the prepared catalyst in toluene media. Methyl aluminoxane (MAO) was used as a cocatalyst. The effect of the [Al] : [Fe] molar ratio, polymerization temperature, and monomer pressure of 202,000 to 454,500 Pa on the polymerization behavior were studied. The highest activity of the catalyst was obtained at 30°C, the activity decreased with increasing temperature, while increasing pressure linearly increased its activity. The molecular weight distribution of the polyethylene obtained was 1.25 to 1.72. A weight average molecular weight of 7.1 × 104 and 1.5 × 103 were obtained. The crystallinity of the polymer was about 19% and its melting point was about 65°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1517–1522, 2007 相似文献
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The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene. In particular, two types of catalysts were investigated, which were N-catalyst (BRICI) and improved polyethylene catalyst. The effects of catalyst structure on kinetic behavior were examined. The distribution of active centers in these catalysts was investigated by energy dispersive analysis by X-rays (EDAX), and morphologies of catalyst particles and polymer products were examined by scanning electron microscope (SEM). Hydrogen response and copolymerization performance were investigated and compared with the two catalysts. The results were correlated with the kinetic behavior of the two catalysts and appropriate models for polymer particle growth were presented. The improved polyethylene catalyst showed higher activity, better hydrogen response and copolymerization performance. 相似文献