oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
X-ray photoelectron spectroscopic analysis of effect of EB on electronic state of Ti species in TiCl4/MgCl2/EB Ziegler-Natta catalysts
Yang Song,Mingzhi Gao,Xi Zhao,Bingquan Mao
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-1393-9
Abstract: X-ray photoelectron spectroscopy (XPS) analysis was performed on TiCl4/MgCl2/EB (ethyl benzoate) catalysts, TiCl4/MgCl2 internal donor free catalysts and TiCl4·EB complex to elucidate the effect of EB on electronic state of Ti species in TiCl4/MgCl2/EB catalysts. Combined with FTIR analysis, the way that EB influenced electronic state of Ti species was postulated. XPS results showed that the binding energy of Ti2p3/2 in TiCl4/MgCl2/EB catalysts was lower than that in TiCl4/MgCl2 internal donor free catalysts indicating that EB influenced electronic state of Ti atoms by providing electrons to Ti atoms in TiCl4/MgCl2/EB catalysts.
X-ray photoelectron spectroscopic analysis of effect of EB on electronic state of Ti species in TiCl4/MgCl2/EB Ziegler-Natta catalysts
SONG Yang,GAO Mingzhi,ZHAO Xi,MAO Bingquan,
SONG
,Yang,GAO,Mingzhi,ZHAO,Xi,MAO,Bingquan

科学通报(英文版) , 2006,
Abstract: X-ray photoelectron spectroscopy (XPS) analysis was performed on TiCl4/MgCl2/EB (ethyl benzoate) catalysts, TiCl4/MgCl2 internal donor free catalysts and TiCl4·EB complex to elucidate the effect of EB on electronic state of Ti species in TiCl4/MgCl2/EB catalysts. Combined with FTIR analysis, the way that EB influenced electronic state of Ti species was postulated. XPS results showed that the binding energy of Ti2p3/2 in TiCl4/MgCl2/EB catalysts was lower than that in TiCl4/MgCl2 internal donor free catalysts indicating that EB influenced electronic state of Ti atoms by providing electrons to Ti atoms in TiCl4/MgCl2/EB catalysts.
Effect of EtOH/MgCl2 Molar Ratios on the Catalytic Properties of MgCl2-SiO2/TiCl4 Ziegler-Natta Catalyst for Ethylene Polymerization  [PDF]
Supanan Patthamasang,Bunjerd Jongsomjit,Piyasan Praserthdam
Molecules , 2011, DOI: 10.3390/molecules16108332
Abstract: MgCl2-SiO2/TiCl4 Ziegler-Natta catalysts for ethylene polymerization were prepared by impregnation of MgCl2 on SiO2 in heptane and further treatment with TiCl4. MgCl2·nEtOH adduct solutions were prepared with various EtOH/MgCl2 molar ratios for preparation of the MgCl2-supported and MgCl2-SiO2-supported catalysts in order to investigate the effect on polymerization performance of both catalyst systems. The catalytic activities for ethylene polymerization decreased markedly with increased molar ratios of [EtOH]/[MgCl2] for the MgCl2-supported catalysts, while for the bi-supported catalysts, the activities only decreased slightly. The MgCl2-SiO2-supported catalyst had relatively constant activity, independent of the [EtOH]/[MgCl2] ratio. The lower [EtOH]/[MgCl2] in MgCl2-supported catalyst exhibited better catalytic activity. However, for the MgCl2-SiO2-supported catalyst, MgCl2 can agglomerate on the SiO2 surface at low [EtOH]/[MgCl2] thus not being not suitable for TiCl4 loading. It was found that the optimized [EtOH]/[MgCl2] value for preparation of bi-supported catalysts having high activity and good spherical morphology with little agglomerated MgCl2 was 7. Morphological studies indicated that MgCl2-SiO2-supported catalysts have good morphology with spherical shapes that retain the morphology of SiO2. The BET measurement revealed that pore size is the key parameter dictating polymerization activity. The TGA profiles of the bi-supported catalyst also confirmed that it was more stable than the mono-supported catalyst, especially in the ethanol removal region.
TiCl4在?-MgCl2(110)表面相互作用的分子模拟  [PDF]
谢克锋,王霞,宋赛楠,刘强,薛山
化工进展 , 2012,
Abstract: 利用基于密度泛函理论的量子力学从头计算方法对TiCl4和其失去部分Cl原子后的离子[TiCl3]+、[TiCl2]2+、[TiCl]3+在β-MgCl2(110)面上的吸附作用进行了研究。通过模拟计算其吸附能、键长和电子云分布,发现TiCl4和β-MgCl2(110)面上作用力很弱,而只有TiCl4失去部分Cl原子后带上正电荷,才能与β-MgCl2(110)面形成强的化学键。
光电子能谱分析TiCl4/MgCl2/EB Ziegler-Natta催化剂中EB对Ti电子状态的影响
宋阳
科学通报 , 2006,
Abstract: 采用光电子能谱(XPS)直接分析了TiCl4/MgCl2/EB(苯甲酸乙酯),TiCl4/MgCl2无内给电子体Ziegler-Natta催化剂和TiCl4·EB配合物中Ti2p3/2结合能的变化,阐明了TiCl4/MgCl2/EB催化剂中EB对Ti电子状态的影响,结合红外分析推断了EB影响Ti电子状态的方式.XPS分析显示TiCl4/MgCl2/EB催化剂的Ti2p3/2结合能低于TiCl4/MgCl2无内给电子体催化剂的Ti2p3/2结合能,说明在TiCl4/MgCl2/EB催化剂中EB通过向Ti提供电子影响Ti的电子状态.
光电子能谱分析TiCl4/MgCl2/EBZiegler-Natta催化剂中EB对Ti电子状态的影响  [PDF]
宋阳,高明智,赵曦,毛炳权
科学通报 , 2006,
Abstract: 采用光电子能谱(XPS)直接分析了TiCl4/MgCl2/EB(苯甲酸乙酯),TiCl4/MgCl2无内给电子体Ziegler-Natta催化剂和TiCl4·EB配合物中Ti2p3/2结合能的变化,阐明了TiCl4/MgCl2/EB催化剂中EB对Ti电子状态的影响,结合红外分析推断了EB影响Ti电子状态的方式.XPS分析显示TiCl4/MgCl2/EB催化剂的Ti2p3/2结合能低于TiCl4/MgCl2无内给电子体催化剂的Ti2p3/2结合能,说明在TiCl4/MgCl2/EB催化剂中EB通过向Ti提供电子影响Ti的电子状态.
TiCl4/MgCl2负载型烯烃聚合催化剂活性中心性质的研究  [PDF]
范志强,封麟先,杨士林
高分子学报 , 1993,
Abstract: 用乙酰氯淬灭法测定了TiCl4/MgCl2-AlR3催化1-辛烯聚合体系的活性中心数,确定了不同助催化剂、外加给电子体等条件下聚合速率、活性中心数、增长速率常数等随聚合时间的变化。结合对产物分子量分布的分峰拟合研究,确定了催化剂上存在多种活性中心及其聚合特性的差别,并发现有机给电子体对某些活性中心有选择性作用,使其失活或改变性质。
无机/有机复合载体SiO2/MgCl2·xBu(OH)2/PSA负载TiCl4催化剂的制备及其乙烯聚合行为  [PDF]
杜丽君,蒋斌波,王靖岱,阳永荣,廖祖维,吴文清
化工学报 , 2010,
Abstract: 采用SiO2、MgCl2以及苯乙烯-丙烯酸共聚物(PSA)合成了SiO2/MgCl2·xBu(OH)2/PSA无机/有机复合载体并负载TiCl4,得到具有SiO2无机支撑层、MgCl2·xBu(OH)2加合物以及服务把本文推荐给朋友Ziegler-Natta催化剂复合载体乙烯聚合”几篇好文章,特向您推荐。请点击下面的网址:"name="neirong">加入引用管理器E-mailAlertRSS作者相关文章
球形TiCl4/MgCl2催化剂引发丙烯气相聚合动力学  [PDF]
胡激江,范宏,卜志扬,李伯耿
化工学报 , 2006,
Abstract: 采用微机在线控制的半连续烯烃聚合反应器,在加压条件下进行了球形TiCl4/MgCl2催化剂催化的丙烯气相聚合,测定了单体瞬时聚合速率等重要的动力学数据,考察了不同聚合条件对聚合动力学的影响,并用Flory-Huggins方程估算了聚合物非晶区中的单体浓度Cm.研究表明聚合速率与Cm成正比;丙烯聚合速率在反应一开始就迅速衰减,之后是缓慢的衰减.提出了一个n级衰减的丙烯气相聚合动力学模型,根据实验数据拟合得到了模型的各个参数,其中活性中心的衰减级数为2.5,气相聚合的表观增长活化能为77.1kJ?mol-1.用该模型可以较好地模拟加压条件下的丙烯气相聚合动力学行为.
丙烯聚合用TiCl4/MgCl2催化剂的研究——聚合温度和烷基铝的影响  [PDF]
钟赤锋,高明智,毛炳权
高分子学报 , 2006,
Abstract: 研究了不同助催化剂和不同聚合温度对催化剂TiCl4/MgCl2/9,9-双(甲氧基甲基)芴(BMMF)丙烯聚合性能的影响.研究结果发现该催化剂在高温(100℃)聚合时,采用还原能力和络合能力较弱的烷基铝(Hex3Al)为助催化剂可以得到高的立构选择性(97%)和高活性.100℃聚合时不同的助催化剂对催化剂得到的聚丙烯结构有重要影响.助催化剂为Me3Al聚合得到的中等等规聚丙烯含量比其他烷基铝高.助催化剂为Et3Al聚合得到聚丙烯链结构中含有少量乙烯共聚单元;而助催化剂为Me3Al,iBu3Al和Hex3Al聚合得到聚丙烯链结构中没有发现共聚单元.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.