Polymerization of propylene with highly active MgCl2-supported TiCl3 catalyst

Summary The MgCl₂ supported TiCl₃ catalyst was prepared by grinding the mixture of TiCl₃·3Py and MgCl₂ in a ball mill. The catalyst was treated either i.vac. at 50–200°C or with alkylaluminum halides to remove the residual pyridine, and propylene polymerization was conducted at 65°C using the resulting catalysts combined with triethylaluminum. The catalyst treated with diethylaluminum chloride showed an extremely high activity for the polymerization.     

新型MgCl_2负载钛催化剂在丙烯聚合中的应用

用优化乳化法制备了MgCl_2负载钛催化剂,考察了催化剂的形态结构并将其应用于丙烯催化聚合。聚合温度70℃、氢气加入量为1 L,采用二异丁基二甲氧基硅烷作为外给电子体时,催化剂具有较高的催化活性,同时聚丙烯具有较高的等规指数。     

Copolymerization of propylene with a small amount of ethylene using a MgCl2/TiCl4 and a TiCl3 catalyst system

Summary Copolymerization of propylene with a small amount of ethylene and homopolymerization of propylene were performed using a highly active MgCl₂/TiCl₄-Et₃Al/ethyl benzoate(EB) and a conventional TiCl₃-Et₂AlCl catalyst systems. The obtained polymers were fractionated into n-decane (C₁₀) soluble and insoluble portions. In all homopolymer fractions with the investigated catalyst systems and copolymer fractions with TiCl₃ catalyst system, the inversion of the direction of arrangement of the propylene unit was not observed by ¹³C-NMR analysis. On the other hand, in C₁₀ soluble fractions of copolymer using MgCl₂/TiCl₄ catalyst system, regardless of the presence of EB, a significant amount of the inversion unit was detected.     

Studies on highly active coordination catalysts for polymerization of α-olefins: 3. Polymerization of propylene with MgCl2/TiCl4/AlEt3 or MgCl2/PhCOOC2H5/TiCl4/AlEt3 systems

Activity and stereospecificity of the $\text{MgCl}{}_2\text{TiCl}{}_4$ catalyst in the polymerization of propylene follow curves showing maxima with grinding time of the MgCl₂ support. Using MgCl₂/PhCOOC₂H₅/TiCl₄ catalysts, no decrease in activity and stereospecificity was observed presumably because of complex formation between MgCl₂ support and ethyl benzoate.     

Ethylene-propylene copolymers by a supported Ziegler-Natta catalyst based on TiCl4/MgCl2

Ethylene-propylene copolymers have been prepared by using Ziegler-Natta catalysts based on TiCl₄, MgCl₂, PCl₃ and (n-Bu)₃PO₄. The catalysts TiCl₄/MgCl₂/PCl₃ and TiCl₄/MgCl₂/(n-Bu)₃PO₄ were prepared by reacting TiCl₄ with pretreated MgCl₂. The support was prepared by ball milling of MgCl₂ with varied amounts of PCl₃ or (n-Bu)₃PO₄. The addition of PCl₃ has remarkably increased the MgCl₂ surface area in comparison with (n-Bu)₃PO₄. The effects of PCl₃ and (n-Bu)₃PO₄ on ethylene homopolymerization, ethylene-propylene copolymerization and on copolymer properties were evaluated. The catalyst system containing PCl₃ permitted to synthesize propylene-ethylene copolymers with up to 75% (w/w) of propylene and provided control of copolymer crystallinity. The reduction of the copolymer molecular weight distribution suggested that PCl₃ acted as an internal donor, poisoning some active catalytic sites. Received: 2 April 1997/Revised: 6 June 1997/Accepted: 18 June 1997     

MgCl2-BuOH/TiCl4催化剂催化乙烯聚合动力学

研究了MgCl2-正丁醇/TiCl4催化剂常压下催化乙烯聚合的性能和动力学行为.考察了n(Al)/n(Ti)、聚合温度、共聚单体浓度、氢气分压对催化剂性能的影响.研究表明:三乙基铝为助催化剂,n(Al)/n(Ti)为200,聚合压力为0.1 MPa,温度为50℃,聚合时间为2 h时,该催化剂具有较高的活性:聚合动力学行为平稳,活性衰减较慢,活性可达1 550.2 g/g;该催化剂具有良好的乙烯均聚合和共聚合性能以及氢调性能.     

Solution copolymerization of ethylene with α-olefins by a MgCl2 supported TiCl4 catalyst

Summary Copolymerization of ethylene with -olefins, i.e. propylene, butene-1, 4-methyl-pentene-1(4-MP-1), was carried out by a MgCl₂ supported TiCl₄ catalyst in combination with Et₃Al at a temperature as high as 170 °C at which the polymerization system was homogeneous. This catalytic system showed very a high activity and produced copolymers having a density of 0.91–0.94 g/ml. Of these three kinds of comonomers, propylene showed the highest reactivity and caused most frequently the termination of a polymer growing by chain transfer reaction and produced copolymers having the broadest MWD.     

SiO2负载二亚胺镍/TiCl4催化乙烯聚合

合成了配合物N,N'-二[4-(4-氨基-3,5-二乙基苄基)-2,6-二乙基苯基]苊二亚胺二氯化镍(NiLCl2),将其与TiCl4复合负载在SiO2/MgCl2上制得负载催化剂.研究了该负载催化剂对乙烯聚合的催化活性, 考察了聚合条件对聚合反应及产物结构的影响.结果表明,负载的NiLCl2/TiCl4较之未负载的NiLCl2催化活性高,最高催化活性达到552 kg/(mol·h),而聚合需要的n(Al)/n(Ni)也较相应的NiLCl2低.     

Kinetics study of slurry-phase propylene polymerization with highly active Mg(OEt)2/benzoyl chloride/TiCl4 catalyst

Propylene was polymerized in a slurry phase over superactive and stereospecific catalyst prepared by the reaction of Mg(OEt)₂ with benzoyl chloride and TiCl₄ in the presence of AlEt₃ with or without an external donor. A kinetic analysis of propylene polymerization was carried out. The polymerization rate was first order with respect to monomer concentration and the dependence of overall polymerization rate on the concentration of AlEt₃ can be explained by the Langmuir adsorption mechanism. Maximum activity was observed around an Al/Ti mole ratio of 20. The average rate over 90 min of polymerization as a function of temperature showed a maximum around 42°C and the overall activation energy was 8.5 kcal/mol at T < 42°C and ?4.0 kcal/mol at T > 42°C. The analysis of the phenomenon of an optimum temperature gave 2.2 kcal/mol for the activation energy of the rate-determining step, and 6.3 kcal/mol, for the adsorption energy of AlEt₃. The addition of small amount of p-ethoxyethyl benzoate (PEEB) as an external donor increased the percentage of isotactic polymer to 98% and slightly increased activity in spite of the decrease in the concentration of active centers due to the stabilizing effect of the active centers by the external donor. The temperature showing maximum yield was shifted to the higher temperature when AlEt₃ and PEEB ([AlEt₃]/[PEEB] = 5) was used as a cocatalyst. © 1994 John Wiley & Sons, Inc.     

Kinetic study on propylene polymerization by a high activity catalyst system: MgCl2/TiCl4/PhCO2Et-AlEt3/PhCO2Et

Summary Kinetic study was performed in short time propylene polymerization with a high activity-high stereospecificity catalyst system composed of MgCl₂/TiCl₄/PhCO₂Et with AlEt₃/PhCO₂Et. The concentration of the active centers, [C ^*], the propagation rate constant, k _p, and the chain transfer rate, r _tr, were determined. The change of these values by the change of polymerization conditions, the concentration of monomer, AlEt₃, and the temperature, were studied.     

MgCl2‐supported catalyst containing mixed internal donors for propylene polymerization

A MgCl₂‐supported catalyst containing diisobutyl phthalate (DIBP) and 2,4‐pentadiol dibenzoate (PDDB) as internal donors was prepared. Propylene polymerizations were carried out using the catalyst in the absence or presence of an external donor. The resulting polymers were characterized by ¹³C‐NMR, crystallization analysis fraction (CRYSTAF) and gel permeation chromatography (GPC). The performance of the catalyst was compared with that of other catalysts containing donor‐free, DIBP and PDDB as internal donors respectively. The results demonstrated that the catalyst containing mixed internal donors not only had high activity and stereospecificity but also produced the polymer with relatively broad molecular weight distribution and the highest [mmmm] value. ¹³C‐NMR analysis results indicated that strongly coordinating donors gave more stereoregular polymers, which was further confirmed by CRYSTAF data. The effects of mixed internal donors on the catalyst properties were discussed systematically. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

MgCl2-BuOH/TiCl4催化剂催化乙烯聚合

研究了自制MgCl2-BuOH/TiCl4催化剂在不同条件下用于乙烯均聚合和共聚合的性能,考察了不同的氢气分压、铝钛摩尔比和共聚单体浓度对催化剂活性和聚合反应动力学的影响,测试了聚合产品的熔体流动速率、堆密度及拉伸性能等,表征了聚合产品的相对分子质量及其分布、分子链结构,得出了聚合条件对MgCl2-BuOH/TiCl4催化剂及其产品性能影响的一般规律.     

外给电子体对MgCl2负载TiCl4催化剂催化乙烯/丙烯共聚合的影响

采用邻苯二甲酸二异丁酯(DIBP)为内给电子体的Mg Cl2负载Ti Cl4催化剂,考察了在无外给电子体及以环己基甲基二甲氧基硅烷(简称C-donor)、二环戊基二甲氧基硅烷(简称D-donor)、苯基三乙氧基硅烷(简称PTES)为外给电子体的条件下,催化剂对乙烯/丙烯共聚合活性、单体竞聚率、共聚物序列分布和热性能的影响。结果表明,在不同外给电子体作用下,随着乙烯进料比的增加,聚合活性先增加后逐渐减小,并呈现出明显的"共单体效应";DIBP与D-donor有很好的协同效应,二者配合可提高催化剂活性,最高可达8.3 kg(以1 g Ti计);当乙烯/丙烯(摩尔比)为40%~65%时,共聚物链段中乙烯和丙烯分布更均匀,无规度更高,具有更短的平均序列长度;当乙烯/丙烯为50%时,所得共聚物的熔融温度最低,可达108℃,玻璃化转变温度为-48.6℃,表明聚合物具有较好的耐低温性能。     

Kinetic study of ethylene polymerization by highly active silica supported TiCL4/MgCl2 catalysts

The kinetics of ethylene polymerization with TiCl₄/MgCl₂/SiO₂ has been investigated in the range of temperatures between 40 and 90°C and in the range of ethylene pressures between 4 and 12.4 kg/cm². The role of MgCl₂ was discussed from the dependence of the Mg/Ti ratio on the catalytic activity. The polymerzation rate was first order with respect to the monomer concentration and the dependence of the polymerization rate on the concentration of Al(C₂H₅)₃ could be described by the Langmuir–Hinshelwood mechanism. The dependence of initial rate and the time to reach the maximum polymerization rate on the concentration of Al(C₂H₅)₃ was also discussed. Polymerization rates as a function of the polymerization temperature showed a maximum and the activation energy was 11.8 kcal/mol between 50 and 80°C. The polymerization rate decreased with the increase of hydrogen partial pressure. The active site concentration (C^*) was 1.9 × 10^?2 mol/mol Ti by the inhibition method with carbon monoxide.     

Propene polymerization with MgCl2-supported TiCl4/dioctylphthalate catalyst. I. Catalyst behavior

Slurry polymerization of propene using MgCl₂-supported TiCl₄/dioctylphthalate catalysts were carried out in a semibatch reactor at a constant pressure to examine the effects of polymerization conditions on catalyst activity and polymer isotacticity. The catalysts were prepared at 80, 90, and 105°C, which gave different compositions of chemical complexes associated with the diester. Five alkyl aluminums (triethyl, triisobutyl, tri-n-hexyl, tri-n-octyl, and isoprenyl) were studied as cocatalysts. Among these, triethyl aluminum was found to be most effective for the catalysts prepared at 80 and 95°C, and tri-n-hexyl aluminum for the catalyst prepared at 105°C. Dimethoxydiphenyl silane and 2,2,6,6-tetramethylpiperidine were employed to study their effects as an external Lewis base for the catalyst prepared at 105°C. In both cases, a small amount of either base resulted in significant increase in activity and isotacticity, which can be attributed to the high level of phthaloyl chloride complex in the catalyst. © 1995 John Wiley & Sons, Inc.     

球形MgCl_2载体催化剂催化乙烯聚合

制备和分析了不同粒径催化剂及其催化聚合物,研究了球形MgCl_2载体催化剂在乙烯聚合过程中的催化性能和动力学行为。结果表明:大颗粒催化剂的聚合过程中明显存在传热和传质阻力;一定的预聚合可以改善聚合物的形态和堆密度。     

Morphological study of spherical MgCl2.nEtOH supported TiCl4 Ziegler‐Natta catalyst for polymerization of ethylene

Spherical MgCl₂·nEtOH was prepared by adducting ethanol to MgCl₂ using melt quenching method. Effect of molar ratio of [EtOH]/[MgCl₂] = 2.8–3.05 on the morphology and particle size of the MgCl₂·nEtOH were studied. The best adduct of spherical morphology was obtained when 2.9 mol ethanol to 1 mol MgCl₂ was used. An emulsion of dissolved MgCl₂ in ethanol was prepared in a reactor containing silicon oil. Stirrer speed of the emulsion and its transfer rate to quenching section that work at ?10 to ?40°C are affected by the particle size of the adduct particle. The adducted ethanol was partially removed with controlled heat primary to catalyst preparation (support). Treatment of the support with excess TiCl₄ increased its surface area from 13.1 to 184.4 m²/g. Heterogeneous Ziegler‐Natta catalyst system of MgCl₂ (spherical)/TiCl₄ was prepared using the spherical support. Scanning electron microscopy studies of adduct, support, and catalyst obtained shown spherical particles, however, the polyethylene particles obtained have no regular morphology. The behavior indicates harsh conditions used for catalyst preparation, prepolymerization, and polymerization method used. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3829–3834, 2006