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对烯烃聚合催化剂的发展状况进行了简要综述,主要包括茂金属催化剂和后过渡金属催化剂(α-二亚胺镍催化剂、N-O型配体催化剂、吡啶类催化剂、α-二亚胺钯催化剂)。最后,对聚烯烃的催化剂的研发进行了展望。 相似文献
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叙述了近几年α,α′-二亚胺配体的后过渡烯烃聚合催化剂的研究近况,及关于此类催化剂负载化的最新研究成果。具有α,α′-二亚胺配体的后过渡金属催化剂备受关注,这类催化剂是具有高活性的单活性中心催化剂,有良好的分子剪裁性,可以在分子层次上实现烯烃聚合的分子设计与组装。 相似文献
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单茂金属化合物催化烯烃聚合 总被引:1,自引:0,他引:1
综述了单茂金属化合物催化烯烃聚合的机理及研究进展,指出IVB族元素钛、锆、铪的单茂金属化合物催化烯烃及α-烯烃的均聚和共聚的活性很好,并通过改变配体结构及聚合条件可得到立构规整性的聚合物,桥联的单茂金属化合物催化乙烯,丙烯聚合的活性相当高,可得到高间规度的聚丙烯和支化的超低密度聚乙烯,但催化苯乙烯的活性很低,VB族元素钒,铌、钽的单茂金属化合物作为烯烃催化剂可得到分子量分布相当窄(1.05)的聚烯烃,另外,单茂铬化合物在很低的Al/Cr(45-100)下具有相当高的催化活性,单茂镍化合物由于其亲氧性小,可催化极性单体(如甲基丙烯酸甲酯等)聚合。 相似文献
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《合成树脂及塑料》2003,20(1):83-84
本发明属于高分子化“茂后”α-双亚胺镍基烯烃聚合催化剂的制备和催化烯烃聚合,催化剂由A和B两组分组成,A组分表达式为[(P(s-co-Cat)]或[SiO2-P(S-co-Cat)],P表示共聚物,S为聚苯乙烯,co表示共聚,Cat表示1-4种“茂后”α-双亚胺镍基催化剂,P(S-co-Cat)是由1-4和α-双亚胺中性配体与金属Ni所形成的配位化合物,其中胺的对位上含有烯烃基团,与苯乙烯共聚得到高分子化“茂后”烃聚合催化剂,SiO2表示高分子化α-双亚胺镍基催化剂[P(S-co-Cat)的二氧化硅载体固载化,B组分为甲基铝氧烷或五氟苯硼[B(C6F5)3]其中任意一种,这类催化剂催化乙烯聚合具有较高的活性,适合气相和淤浆聚合工艺,聚合物不含无机灰分。 相似文献
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按配体类型,综述了近年来第ⅣB族非茂金属烯烃聚合催化剂研究进展,其配体类型包括:胺基类、酮亚胺类、吡唑类、苯氧亚胺类等。讨论了配体结构和电子效应对催化剂聚合活性及聚合物结构、分子量等的影响;概括了高活性第ⅣB族非茂金属烯烃聚合催化剂应具备的条件。 相似文献
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本研究以2,6-二乙酰基吡啶、2,4,6-三甲基苯胺和FeCl2.4H2O为原料,制备了后过渡金属铁的二亚胺配合物。将其负载在改性蒙脱土上,以己烷为溶剂、AlEt3为助催化剂进行聚合反应。通过红外光谱、X射线分析、热分析等,系统地研究了蒙脱土的改性条件对蒙脱土结构、蒙脱土载体铁系催化剂的聚合行为及聚合物结构与热性能的影响。研究表明最佳插层条件是:1831为插层剂、80℃、反应2 h、蒙脱土/1831(质量比)为3/1,此时层间距为2.72 nm,催化剂活性达1.073×106(g PE/mol Fe.h),聚乙烯堆密度为0.351g/cm3,形成MMT/PE纳米塑料。 相似文献
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Bijal Kottukkal Bahuleyan Jae Min Oh Deepak Chandran Ju Young Ha A Young Hur Dae-Won Park Chang Sik Ha Hongsuk Suh Il Kim 《Topics in Catalysis》2010,53(7-10):500-509
A facile and user friendly technique to immobilize late transition metal complexes on nonporous silica has been developed. Among the supported diimine Ni(II) and iminopyridyl Fe(II) catalysts, former showed high activities exceeding 105 g-PE mol-metal?1 h?1 bar?1 combined with ethylaluminum sesquichloride. The obtained polymer morphology was tunable from spherical to fibrous shape. 相似文献
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Modification of ethyl‐iso‐butylaluminoxanes (EBAOs) with alkyl boronic acid resulted in different co‐catalytic performances when combined with iron complexes for ethylene polymerization, in particular the preferred high‐temperature performance. The changes in polymerization activity and molecular weight distribution of the resulting polymer derived from the variation of aluminoxane were investigated. The varying performance of the iron complex with different aluminoxanes has proved that the interaction between the late transition metal complex and aluminoxane greatly affects the performance of such bicomponent catalyst systems Copyright © 2003 Society of Chemical Industry 相似文献
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介绍了α-二亚胺配体后过渡金属烯烃聚合催化剂的研究进展,对此类催化剂因改变配体空间位阻、改变配体取代基电子效应而对催化活性、相对分子质量、分子结构的影响进行了综述。三联苯基配体催化剂兼具高活性和高稳定性,刚性环和轴向给电子基团有机结合的α-二亚胺配体后过渡金属催化剂具有高活性、产物高相对分子质量、高线型、低支化度的特点,为新型催化剂的制备以及新型材料的合成提供了新思路。 相似文献
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概述了新型高活性后过渡金属Fe(Ⅱ)、Co(Ⅱ)催化剂的结构、合成及其催化乙烯、丙烯均聚的性能。此类催经剂是以带有大取代基的吡啶二亚胺为主配体的五配位络合物,在甲基铝氧烷等助催化剂的激活下具有极高的活性,而且制备简单,催化丙烯聚合时产物等规指数超过以往的各类催化剂,并介绍了其催化机理。 相似文献
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Yiyoung Choi 《Polymer》2010,51(11):2271-693
MgCl2/alcohol adducts were recrystallized with alkyl aluminums and used as catalysts supports for nickel diimine complexes functionalized with amine groups. These supported catalysts were used to polymerize ethylene in a slurry reactor. The MgCl2-based supported nickel diimine catalysts had higher activities than the equivalent SiO2-supported nickel diimine catalysts, even without the use of activators. These catalysts made polyethylene with melting temperatures and molecular weights higher than those made with the equivalent homogeneous catalysts. Interestingly, the catalyst activity and polymer molecular weight could be controlled by changing the support composition. In addition, covalent chemical bonds between the functionalized nickel diimine complex and the MgCl2-based supports avoided catalyst leaching during polymerization, leading to the production of polymer particles with good morphology. The mechanical strength of the resulting polymer particles, however, was lower than those made with SiO2-supported nickel diimine catalysts. 相似文献
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Polyolefins containing 1,3‐disubstituted cyclopentane units in the main chain have been synthesized by 1,3‐polymerization of cyclopentene (PCP), cyclization polymerization of 1,5‐hexadiene (PHD), and ring‐opening metathesis polymerization of norbornene following hydrogenation of the unsaturated main chain (H‐PNB) with various transition metal catalysts. These polyolefins were applied to nucleating agents for isotactic polypropylene, and relationship between the structure of the polyolefins and nucleating effect was studied by DSC, polarized optical microscope, and WAXD. All the polyolefins had an effect of nucleation for isotactic polypropylene (PP). Of the polymeric nucleating agents, H‐PNB showed the most effective nucleation. Addition of PCP, which was obtained with a nickel catalyst with diimine ligand, to PP induced β‐modification. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2953–2958, 2006 相似文献