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1.
高分子化铁系烯烃聚合催化剂的合成及乙烯聚合   总被引:1,自引:0,他引:1  
刘长坤  金国新 《化学学报》2002,60(1):157-161
合成了含烯丙基不对称型的“茂后”催化剂[ArN=C(Me)][Ar'N=C(Me)]C~5H~3NFeCl~2[Ar=2,6-(i-Pr)~2C~6H~3,Ar'=4-烯丙基-2,6-(i-Pr)~2C~6H~3],通过IR,^1HNMR,EI-MS,EA对化合物进行表征。利用这个催化剂上的烯烃基团在自由基引发下与苯乙烯共聚,制备出高分子化的“茂后”催化剂。研究了高分子化前后催化剂催化乙烯聚合行为,高分子化的催化剂在常压13℃下催化乙烯聚合时,活性最高达到2.5×10^6gPE/molFe.h,高于未高分子化之前催化剂的活性。证明了高分子化是“茂后”催化剂理想的固载化方式。  相似文献   

2.
陈正军  张道  金国新 《无机化学学报》2005,21(12):1775-1783
选择含有烯丙基亚胺酚为辅助配体,设计合成了5个ⅣB族钛锆金属络合物[{CH2=CHCH2N=CH-C6H3(3-R)O}2MCl2](4aR=t-Bu,M=Zr;4bR=t-Bu,M=Ti;4cR=Ph,M=Zr;4dR=Ph,M=Ti)和[{(CH3)2CHCH2N=CH-C6H3(3-t-Bu)O}2ZrCl2] (5),对它们进行了红外光谱、核磁共振及元素分析表征。并用X-射线单晶衍射法测定了化合物4a4d的晶体结构。部分配合物在助催化剂MMAO的作用下对烯烃聚合显示了较好的催化活性,其中自固载催化剂4a生成了双峰分布的聚烯烃产品 (Mw/Mn=15.3~31.9)。  相似文献   

3.
诸海滨  金国新 《化学学报》2002,60(3):509-513
合成了硅桥上含乙烯基团的硅桥联茂金属催化剂[(CH_2=CH)CH_3Si(C_5H_4) _2]ZrCl_2 (3),并通过IR, ~1H NMR对化合物进行了表征,3在AIBN的引发下与苯 乙烯共聚形成高分子化的茂金属催化剂4。研究了3和4对乙烯聚合的能力,考察了 n(Al)/n(Zr)'温度对催化剂活性的影响。  相似文献   

4.
合成了烯丙基取代的含氮中性配体 [( p-C3H5) C12 H16]2 N3C9H9,然后与 Fe Cl2 反应合成含烯丙基取代的三齿“茂后”烯烃聚合催化剂 [( p-C3H5) ( C12 H16) ]2 N3C9H9Fe Cl2 ,通过 IR,1H NHR,EI-MS对化合物进行了表征 .研究了它催化乙烯聚合的能力 ,这种催化剂与 MAO组成的催化体系可在常压下催化乙烯聚合 ,活性最高达 1 .9× 1 0 6g PE/ ( mol Fe· h) .所得聚乙烯粘均分子量在 5× 1 0 4 ~ 2 .6× 1 0 5之间  相似文献   

5.
烯烃聚合催化剂技术的发展关系着聚烯烃工业的命脉,而第ⅣB族非茂金属烯烃聚合催化剂作为目前催化剂研究的热点之一,不仅具有催化活性高、共聚单体范围广以及聚合物结构可控等优点,并且相比于茂金属催化剂而言,合成简单、成本低廉,有利于丰富烯烃聚合催化剂的种类和开发新型聚烯烃产品。本文按照配体的价齿类型综述了近十年来第ⅣB族非茂金属烯烃聚合催化剂的结构特点,及其在烯烃均聚和共聚反应中的催化性能,讨论了配体的电子效应和位阻效应对于配合物催化活性以及所得聚合物的结构、分子量等性质的影响,并对相关领域的未来发展提出了建议。  相似文献   

6.
合成和表征了2个锆的配合物:Bis[N-(3-tert-butylsalicylidene) allylaminato] zirconium dichloride (4)和Bis[N-(3-tert-butylsali-cylidene)-iso-butylaminato] zirconium dichloride (5),并且得到了配合物4的单晶结构。在引发剂的作用下,配合物4和苯乙烯进行自由基共聚,得到高分子化催化剂6。在助催化剂MMAO的存在下,4,56都可以催化乙烯聚合。最高活性为3.7×106 g PE·(mol Zr)-1·h-1。  相似文献   

7.
以茂金属化合物[(CH3)2C(η-C5H3)(η-C9H6)]ZrCl2为主催化剂,甲基铝氧烷MAO为助催化剂催化乙烯聚合,对不同的反应条件下(如温度,铝锆摩尔比)聚合反应的动力学进行了研究,并根据此聚合反应体系的动力学特点及考虑到活性中心的再活化,在分析和研究以往的动力学模型的基础上,对烯烃均相聚合动力学反应作了一些假定,建立了动力学模型,用模型对实验数据进行了拟合,结果表明与实验数据相吻合,可以认为,在该聚合反应体系中,确实存在铝氧烷的再活化作用,根据模拟拟合得到了聚合反应的动力学参数。  相似文献   

8.
合成了二双齿钛催化剂[C3H6(N=CH-Ar-O)2]TiCl2(Ar=3-tert-butyl-C6H3),并通过X-射线单晶衍射分析测定了其晶体结构。应用新型介孔分子筛SBA-15为载体,成功地对其进行了物理和化学负载,并采用元素分析、ICP、FT-IR和XRD等对载体催化剂进行了表征。在甲基铝氧烷(MAO)的作用下进行乙烯聚合研究,结果表明载体催化剂活性虽然比二双齿钛均相催化剂的活性有所降低,但是由于载体孔道效应生成了纤维状聚乙烯,同时聚合物的分子量较均相催化剂得到的聚合物有大幅度提高。  相似文献   

9.
Ziegler-Natta催化剂催化乙烯气相聚合   总被引:1,自引:0,他引:1  
伍青  王海华 《高分子通报》1993,(4):248-252,247
本文综述了乙烯气相聚合催化剂研究状况,列举了一些制备气相聚合催化剂有代表性的方法。同时对预聚合的作用及气相聚合与淤浆聚合表观动力学行为的不同性也作了简要介绍。  相似文献   

10.
预聚合条件对高效催化剂催化乙烯气相聚合的影响   总被引:1,自引:0,他引:1  
采用经预聚合处理的MgCl2负载的钛系催化剂进行乙烯气相聚合和淤浆聚合比较.乙烯淤浆聚合其表观动力学呈现为加速型或渐升衰减混合型,而气相聚合则为衰减型.在聚合前期阶段,气相聚合速度明显高于淤浆聚合速度.这样的差别是由于淤浆聚合中明显存在着单体在颗粒中扩散受阻的影响,气相聚合中则存在过热现象.测定了两种聚合方式中催化剂的钛价态,结果表明气相聚合条件下钛的价态分布比淤浆聚合更大程度倾向于低价态.催化剂预聚合温度和预聚合产率对气相聚合活性及表观动力学行为的影响表明预聚合工艺是气相聚合反应平稳控制有效技术.  相似文献   

11.
简要介绍了新型的烯烃聚合催化剂-Ni(Ⅱ)、Pd(Ⅱ)、Fe(Ⅱ)、Co(Ⅱ)类后过渡金属催化剂的发展,特点及催化乙烯聚合机理,并就它们的组成结构、聚合条件和配体体积对聚合产物结构,分子量等的影响根据配体不同分类进行了讨论。  相似文献   

12.
A FI (phenoxy-imine) Zr-based catalyst of bis[1-[(2,6-diisopropylphenyl)imino]methyl-3,6-ditertbutyl-2-naphtholato]zirconium(IV) dichloride was prepared by changing the ligand from salicylaldehyde imine ligand which is used for well known FI catalysts to 2-hydroxynaphthalene-1-carbaldehyde imine ligand and used for polymerization of ethylene. Replacement of the phenoxy-group by naphtholato-group does not provide any spatial difficulties in the ortho-position to oxygen, but introduction of the bulky alkyl substitution groups at the ortho position of the naphthoxy-oxygen and on phenyl ring on the N dramatically enhanced the activity of the catalyst, as well as viscosity average molecular weight (Mv) of the obtained polymer. The prepared catalyst could produce a high molecular weight polyethylene under the polymerization conditions used. The optimum activity of the catalyst was obtained at the reaction temperature of 40°C. Activity of the catalyst was continuously increased with increasing MAO concentration and monomer pressure and no optimum activity was observed in the range studied. Crystallinity and melting point of the obtained polymer were between 55–65% and 125–135°C, respectively. A molecular weight distribution of 1.55–2.75 was obtained under the polymerization condition used and the polydispersity was broadened with the time. The activity of the catalyst was not sensitive to the hydrogen concentration. However, higher amount of hydrogen could slightly increase the activity of the catalyst.  相似文献   

13.
冯作锋  黄吉玲  钱延龙  孙俊全  陈伟 《中国化学》2002,20(11):1401-1405
IntroductionItiswellknownthatmetallocenesactivatedwithmethylaluminoxane (MAO)arehighlyactivehomogeneousZiegler Nattacatalyststhatproducepolyolefinwithcon trolledstereoregularityandnarrowmolecularweightdistri bution ,1 4 however,themolecularweightofthepolym…  相似文献   

14.
王新科  Sit  Met-Met  孙杰  唐勇  谢作伟 《化学学报》2012,70(18):1909-1916
通过给电子基团取代的(E)-2,4-二-叔丁基-6-(苯基亚胺基甲基)苯酚与等当量的M(CH2Ph)4 反应制备了一系列第四族金属的双苄基配合物. 反应经历了甲苯消除及分子内苄基从金属至亚胺碳的迁移反应, 中间体的分离和结构鉴定证实了该反应历程. 通过核磁、元素分析和X-ray 单晶衍射表征了配合物的结构. 在甲基铝氧烷(MMAO)的活化下, 钛配合物可以高活性地催化乙烯的均聚合和乙烯/1-己烯的共聚合, 而相应的锆、铪的配合物在同样的条件下则几乎没有活性.  相似文献   

15.
A series of 2,6-bis(imino)pyridyl iron and cobalt complexes bearing p-substituent [2,6-(ArN=CMe)2C5H3N]- MCl2 (Ar=2,6-Me2C6H3, 2,4,6-Me3C6H2, 2,6-Me2-4-BrC6H2, 2,6-Me2-4-ClC6H2, 2,4-Me2-6-BrC6H2, 2,4-Me2-6- ClC6H2, while M=Fe, Co) have been synthesized and investigated as catalysts for ethylene polymerization in the presence of modified methylaluminoxane as a cocatalyst. The electron effect and positions of the substituent of pyridinebisimine ligands were observed to affect considerably catalyst activity and polymer property.  相似文献   

16.
Syntheses of titanatranes containing [(O-2,4-Me2C6H2-6-CH2)2-{O(CH2)nCH2}]N3− (n = 1,2) have been explored. Catalytic activity for ethylene polymerization by Ti2(OiPr)2{[(O-2,4-Me2C6H2-6-CH2)22-OCH2-CH2)]N}2 ( 1a ) - MAO catalyst increased at high temperature; the activity also increased upon addition of AlMe3. Ti(O- 2,6-iPr2C6H3){[(O-2,4-Me2C6H2-6-CH2)2(OCH2CH2)]N} ( 1c ) showed higher activity than 1a under the same conditions. Ti{[(O-2,4-Me2C6H2-6-CH2)2(HOCH2CH2CH2)]N}2 was isolated from the reaction of Ti(OiPr)4 with bis(2-hydroxy-3,5-dimethylbenzyl)-propanolamine; the structure was determined by X-ray crystallography.  相似文献   

17.
新型聚合物载体茂金属催化剂   总被引:4,自引:0,他引:4  
均相茂金属催化剂虽然有许多优点和特点,但也存在着某些不足之处,例如,不适于现在通用的气相和淤浆聚合工艺;要想达到足够的聚合活性需大量价格昂贵的MAO;相当多的均相茂金属催化剂不适于高温聚合(活性降低,分子极低),不能很好地控制聚合物的形态,为了在工业上得到实际应用,必须将它们载体(非均相)化。通常采用的载体都是无机物,如SiO2、MgCl2、Al2O3等。由于无机载体表面具有酸性,负载茂金属催化剂活性有所降低,用聚合和作茂金属催化剂的载体很少有报道,我们研制了一种新型的聚合物载体茂金属催化剂,即可保持均相茂金属催化特点和优点,又能克服其缺点。其合成路线如下。  相似文献   

18.
Two (SiO2/MgR2/MgCl2)·TiClx model catalysts are made by refluxing TiCl4 with 0.35 wt% Cr modified silica gel/alkyl Mg adducts or silica gel/alkyl Mg adducts, which are named as Cr/Ti‐based bimetallic Cat‐1 and Ti‐based monometallic Cat‐2, respectively. The kinetics, active center counting, morphology, and polymer characterizations are studied to disclose the effect of low loading Cr active sites on the Cr/Ti‐based bimetallic Cat‐1 polymerization under mild conditions. The activity of Cat‐1 is 120.4% higher than that of Cat‐2, with a 114.1% higher [C*]/[M] value. Morphology results show the Cat‐1 fragmentation in the first 3 min is highly accelerated, which helps to release buried clustered Ti sites. Differential scanning calorimetry results show that low‐temperature heat absorbing shoulder of polyethylene (PE) from Cat‐2 demonstrates the signal of low crystallinity polymer made by Cat‐2 during the first 60 s, verifying the fluffy polymer in morphology results. GPC results show PE from Cat‐1 has a higher Mw in the first 3 min while a lower Mw in the end. The Cat‐1, which release active sites faster, has a high Mw in the early time. Lower Mw in the 900 s attributes to the effect of relative lower Mw polymer made by Cr sites, compared with Cat‐2.  相似文献   

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