单活性中心茂金属催化剂催化乙烯与1-己烯共聚合

采用自制的单活性中心茂金属催化剂为主催化剂,甲基铝氧烷为助催化剂进行乙烯与1-己烯的共聚合。考察了溶剂、助催化剂用量、反应温度、反应压力、共聚单体浓度等对催化剂活性和共聚物性能的影响。结果表明:单活性中心茂金属催化剂催化乙烯与1-己烯共聚合的适宜溶剂为正庚烷,适宜的工艺条件为n(Al)∶n(Zr)=700~1 000,反应温度100~120℃,反应压力1.20~2.00 MPa,1-己烯浓度1.00~1.84 mol/L。     

使用茂金属催化剂制备聚烯烃弹性体的研究

优化了桥联结构的茂金属催化剂在甲基铝氧烷(MAO)活化下合成乙烯-己烯共聚物的溶液聚合工艺参数。详细考察了Al/Zr摩尔比、聚合反应温度和共聚单体用量等聚合条件对催化剂活性以及聚合产物性能的影响。     

Cp2ZrCl2/三异丁基铝/B(C6F5)3催化体系催化1-辛烯聚合

用Cp₂ZrCl₂/三异丁基铝/B(C₆F₅)₃催化体系对1-辛烯的聚合进行研究,考察催化剂用量、反应温度、反应时间、Al与Zr物质的量比和B与Zr物质的量比等工艺条件的影响。确定1-辛烯齐聚的最佳工艺条件为：催化剂用量0.028 7 mmol,反应温度60 ℃,反应时间60 min,Al与Zr物质的量比为110,B与Zr物质的量比为1.5。     

半炼蜡裂解 1-己烯用于聚乙烯共聚单体研究

以半炼蜡裂解1-己烯为原料,在2L不锈钢釜中进行了与乙烯共聚的淤浆聚合和气相搅拌聚合试验研究,聚合工艺条件为:压力1.03MPa;p(H2)/p(C2H4)=0.28/0.75MPa,1mLAlEt3溶液(1mmol/mL);淤浆聚合和气相搅拌聚合温度分别为80℃和85℃。研究结果表明,半炼蜡裂解1-己烯可以与乙烯进行共聚反应,其共聚性能与进口的1-己烯相当。     

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.     

茂金属/有机硼化物催化体系催化1-癸烯聚合

采用茂金属催化体系Ph_2C(Cp-9-Flu)ZrCl_2/C_6H_5NH(CH_3)_2B(C_6F_5)_4/Al(~iBu)_3催化1-癸烯聚合,考察了催化剂浓度、Al和Zr以及有机硼化物和Zr物质的量之比、反应温度和反应时间等工艺条件对产物的影响,并采用核磁共振对其产物与1-癸烯在Ph_2C(Cp-9-Flu)ZrCl_2/MAO催化下聚合产物的结构进行了分析比较。结果表明:在Zr和1-癸烯物质的量之比为10×10~(-5),硼化物和Zr物质的量之比为1.5,Al和Zr物质的量之比为100,反应温度为60℃的条件下,反应时间120 min,1-癸烯的转化率为93.6%,运动黏度(100℃)为3 684 mm~2/s,黏度指数为367,数均分子量为2.9×10~4,分子量分布为1.85;聚合时单体主要进行1,2插入,产生亚乙烯基端基。     

rac-Et(1-Ind)_2ZrCl_2/MAO催化1-癸烯聚合制备高粘度润滑油

茂金属催化体系具有超高活性和单一活性中心,是催化α-癸烯聚合的理想催化剂。用茂金属催化体系rac-Et(1-Ind)2Zr Cl2/MAO对1-癸烯聚合制备高粘度润滑油基础油进行了研究,提出了反应体系可能的聚合机理。考察了催化剂浓度、Al和Zr物质的量之比、反应温度和反应时间对聚合产物性能的影响。结果表明,在Zr和1-癸烯物质的量之比为8×10-5,Al和Zr物质的量之比为100,反应温度为50℃,反应时间为60 min时,1-癸烯的转化率为91.6%。聚合产物的整体性能较为优异,运动粘度(100℃)为393.9 mm2/s,粘度指数为271,数均分子量为9 091,分子量分布为1.691 3。     

含Ti-Mg-Al配合物的催化剂合成及催化烯烃聚合

合成了一种新型含Ti-Mg-Al配合物(MTA)的聚烯烃催化剂,研究了它的结构及其催化乙烯均聚合及乙烯与1-己烯共聚合的性能。在常压、均相聚合条件下,MTA催化乙烯聚合具有较高的活性,可达2.14×10~5g/(mol·h)。MTA在催化乙烯与1-己烯共聚合时,具有良好的聚合活性。通过改变共聚单体的浓度,可有效调节聚合物的熔点、1-己烯的插入率、相对分子质量及其分布。     

聚合条件对乙烯-1-辛烯共聚反应及性能影响

以甲苯为溶剂,采用自制茂金属催化剂、助催化剂三异丁基铝[Al(~iBu)_3]和三苯碳四(五氟苯基硼)[Ph_3C]~+[B(C_6F_5)_4]~-催化乙烯与1-辛烯共聚,探究了聚合温度和1-辛烯浓度对乙烯-1-辛烯共聚反应以及共聚物结构与性能的影响。结果表明:当聚合温度从100℃升高到150℃时,催化活性下降,共聚物相对分子质量持续降低,其分布则变宽,熔融温度和结晶度均上升;当1-辛烯浓度从0升高到1.2 mol/L时,催化活性显著增大,共聚物相对分子质量分布变宽,熔融温度和结晶度均下降。     

(C2H5)2AlCl/TiCl4催化1-癸烯聚合制备高黏度指数润滑油

以(C₂H₅)₂AlCl/TiCl₄为催化剂研究了1-癸烯聚合制聚烯烃基础油。比较烯烃原料和溶剂对聚α-烯烃性能的影响,探讨催化剂用量、Al与Ti物质的量比、反应时间和反应温度等工艺条件对合成油性能的影响。结果表明,(C₂H₅)₂AlCl/TiCl₄催化剂对1-癸烯聚合具有较高的活性;溶剂极性越大,聚α-烯烃的枝化度越大,从而导致黏度指数降低。100 ℃的运动黏度随着Al与Ti物质的量比不同而变化,因此,可以通过调节Al与Ti物质的量比,制备各种黏度的聚α-烯烃。以(C₂H₅)₂AlCl/TiCl₄ 为催化剂,1-癸烯聚合的最佳反应条件：反应温度80 ℃,反应时间4 h,催化剂用量为反应物总质量的4.0%,此条件下聚α-烯烃收率为75.6%,黏度指数高达173。     

高分子载体负载Cp2ZrCl2/MAO催化剂及其催化乙烯聚合的研究

苯乙烯、2-乙烯基苯和烯丙基取代的茂金属催化剂进行共聚,合成高分子化的茂金属催化剂。该茂金属催化剂用于乙烯聚合反应活性较高,在聚合工艺条件为75 ℃,压力1.4 MPa,n(Al)∶n(Zr)=400时,活性可达1.95×10⁷ g·（mol·h）^－1,并可控制聚合物的形态。     

不同形貌介孔材料催化剂的制备及在乙烯聚合中的应用

利用面包圈状、棒状、高比表面积球状和空心球状4种不同形貌的介孔材料作为载体负载甲基铝氧烷和茂金属双（正丁基环戊二烯基）二氯化锆（BuCp）制备负载型茂金属催化剂,并在2 L不锈钢高压聚合釜进行高压乙烯聚合小试试验。文中研究了4种反应器的组成、结构和微观形貌。扫描电镜、小角X光粉晶衍射、氮气吸附-脱附测试结果表明,4种不同形貌介孔材料在负载茂金属后仍然保持较好微观形貌及其特有的介孔材料孔道结构,负载茂金属后反应器的孔结构参数较负载前有所减小,孔壁厚度有所增强,表明茂金属成功进入介孔材料孔道中。元素分析结果表明,所得催化剂表面的Al元素质量分数范围为16%～22%,Zr元素质量分数范围为0.4%～0.7%。聚合试验结果表明,催化剂对乙烯均聚和共聚的活性均优于当前工业用载体955硅胶负载同样茂金属后的乙烯均聚和乙烯和己烯共聚的活性,其中空心球状介孔材料反应器为最适合乙烯聚合的催化剂。     

负载型茂金属催化剂用于乙烯淤浆聚合的研究

在烯烃催化聚合领域,茂金属催化剂显示出比传统Ziegler-Natta催化剂更高的活性。以苯甲酸催化三甲基铝（TMA）受控水解生成甲基铝氧烷（MAO）,经热解过程后合成了一种不溶形式的固体聚甲基铝氧烷（sMAO）。以合成的sMAO为载体负载茂金属催化剂,并将该催化剂应用于乙烯淤浆聚合反应中,系统探究了聚合条件对催化行为的影响,同时对聚乙烯产品mPE的粒度、堆密度、分子量及分布和熔体流动速率等基本理化性能进行了分析表征。实验结果表明,制备的催化剂颗粒形态较好,粒子分布均匀,在5 L釜中催化淤浆反应,乙烯/1-己烯共聚活性最高可达15 302.6 g·g^-1,并得到了相对分子质量分布均匀的中、高密度聚乙烯产品。     

Comparative study of copolymerization and terpolymerization of ethylene/propylene/diene monomers using metallocene catalyst

(Ind)₂ZrCl₂ catalyst was synthesized and used for copolymerization of ethylene and propylene (EPR) and terpolymerization of ethylene propylene and 5‐ethyldiene‐2‐norbornene (ENB). Methylaluminoxane (MAO) was used as cocatalyst. The activity of the catalyst was higher in copolymerization of ethylene and propylene (EPR) rather than in terpolymerization of ethylene, propylene and diene monomers. The effects of [Al] : [Zr] molar ratio, polymerization temperature, pressure ratio of ethylene/propylene and the ENB concentration on the terpolymerization behavior were studied. The highest productivity of the catalyst was obtained at 60°C, [Al] : [Zr] molar ratios of 750 : 1 and 500 : 1 for copolymerization and terpolymerization, respectively. Increasing the molar ratio of [Al] : [Zr] up to 500 : 1 increased the ethylene and ENB contents of the terpolymers, while beyond this ratio the productivity of the catalyst dropped, leading to lower ethylene and ENB contents. Terpolymerization was carried out batchwise at temperatures from 40 to 70°C. Rate time profiles of the polymerization were a decay type for both copolymerization and terpolymerization. Glass transition temperatures (T_g) of the obtained terpolymers were between ?64 and ?52°C. Glass transition temperatures of both copolymers and terpolymers were decreased with increased ethylene content of the polymers. Dynamic mechanical and rheological properties of the obtained polymers were studied. A compounded EPDM showed good thermal stability with time. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Ziegler-Natta/茂金属复合催化剂制备双峰聚乙烯

通过把茂金属催化剂负载在Ziegler-Natta催化剂上制备了ZM复合催化剂,在单一聚合反应器内研究了ZM催化剂用于乙烯聚合制备双峰聚乙烯的性能。考察了催化剂中茂金属化合物的含量、聚合过程中反应温度、助催化剂的用量和共聚单体1-己烯的用量对催化剂乙烯聚合性能的影响规律。结果表明：采用ZM催化剂可以在单反应器内催化乙烯聚合得到分子量分布呈双峰的聚乙烯,聚乙烯的分子量分布达到155,聚合活性可达2.52×10⁷ g/molMt·h。     

均相茂金属加合物催化乙烯均聚及乙烯／1—己烯共聚

对均相茂金属加合物催化剂催化乙烯均聚和乙烯与１－己烯共聚进行了研究,采用三异丁基铝（ＴＩＢＡ）部分取代助催化剂甲基铝氧烷（ＭＡＯ）,并对共聚单体投料量对聚合的影响进行了考察。发现共聚活性高于均聚活性;用ＴＩＢＡ部分取代ＭＡＯ可以降低ＭＡＯ用量,而且提高了催化活性;１－己烯的投料量对１－己烯的插入量影响较大。     

Effects of aluminum alkyls on ethylene/1‐hexene polymerization with supported metallocene/MAO catalysts in the gas phase

The effects of aluminum alkyls on the gas‐phase ethylene homopolymerization and ethylene/1‐hexene copolymerization over polymer‐supported metallocene/methylaluminoxane [(n‐BuCp)₂ZrCl₂/MAO] catalysts were investigated. Results with triisobutyl aluminum (TIBA), triethyl aluminum (TEA), and tri‐n‐octyl aluminum (TNOA) showed that both the type and the amount of aluminum alkyl influenced the polymerization activity profiles and to a lesser extent the polymer molar masses. The response to aluminum alkyls depended on the morphology and the Al : Zr ratio of the catalyst. Addition of TIBA and TEA to supported catalysts with Al : Zr >200 reduced the initial activity but at times resulted in higher average activities due to broadening of the kinetic profiles, i.e., alkyls can be used to control the shape of the activity profiles. A catalyst with Al : Zr = 110 exhibited relatively low activity when the amount of TIBA added was <0.4 mmol, but the activity increased fivefold by increasing the TIBA amount to 0.6 mmol. The effectiveness of the aluminum alkyls in inhibiting the initial polymerization activity is in the following order: TEA > TIBA >> TNOA. A 2‐L semibatch reactor, typically run at 80°C and 1.4 MPa ethylene pressure for 1 to 5 h was used for the gas‐phase polymerization. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3549–3560, 2004     

The investigation of novel non‐metallocene catalysts with phenoxy‐imine ligands for ethylene (co‐)polymerization

Phthaldialdehyde and phthaldiketone were treated with substituted phenols of 2‐amino‐4‐methylphenol, 2‐amino‐5‐methylphenol and 2‐amino‐4‐t‐butylphenol, respectively, and then treated with transition metal halides of TiCl₄, ZrCl₄ and YCl₃. A series of novel non‐metallocene catalysts (1–12) with phenoxy‐imine ligands was obtained. The structures and properties of the catalysts were characterized by ¹H NMR and elemental analysis. The catalysts (1–12) were used to promote ethylene (co‐)polymerization after activation by methylaluminoxane. The effects of the structures and center atoms (Ti, Zr and Y) of these catalysts, polymerization temperature, Al/M (M = Ti, Zr and Y) molar ratio, concentration of the catalysts and solvents on the polymerization performance were investigated. The results showed that the catalysts were favorable for ethylene homopolymerization and copolymerization of ethylene with 1‐hexene. Catalyst 10 is most favorable for catalyzing ethylene homopolymerization and copolymerization of ethylene with 1‐hexene, with catalytic activity up to 2.93 × 10⁶ gPE (mol Y)^?1 h^?1 for polyethylene (PE) and 2.96 × 10⁶ gPE (mol Y)^?1 h^?1 for copolymerization of ethylene with 1‐hexene under the following conditions: polymerization temperature 50 °C, Al/Y molar ratio 300, concentration of catalyst 1.0 × 10^?4 L^?1 and toluene as solvent. The structures and properties of the polymers obtained were characterized by Fourier transform infrared spectroscopy, ¹³C NMR, wide‐angle X‐ray diffraction, gel permeation chromatography and DSC. The results indicated that the obtained PE catalyzed by 4 had the highest melting point of 134.8 °C and the highest weight‐average molecular weight of 7.48 × 10⁵ g mol^?1. The copolymer catalyzed by 4 had the highest incorporation of 1‐hexene, up to 5.26 mol%, into the copolymer chain. © 2012 Society of Chemical Industry     

Octadecyl-modified silica supports for metallocene catalyst applied in ethylene polymerization

Chemical modification of silica-based supports is an alternative route for modulating the active sites of metallocene catalysts, presenting the potential to obtain polyethylenes with improved properties. Therefore, this work investigates the effect of octadecylsilane content in silica support on the behavior of resulting supported metallocene catalysts on ethylene polymerization. For this propose, a series of octadecyl-modified silicas whit different amounts of octadecyl (ODS) groups were synthesized by a modified Stöber sol–gel method and then applied as supports for a metallocene catalyst. The supported metallocene catalysts were evaluated in ethylene polymerization and ethylene/1-hexene copolymerization reactions. Besides, studies of the growth kinetics of polyethylene particles in a gas phase reactor were performed using videomicroscopy. The octadecylsilane content in the supports was in the range of 0.2 to 1.4 mmol g⁻¹. DRIFTS and ¹³C CP/MAS NMR results showed a predominance of an all-trans octadecyl chain conformation. SEM images showed spherical particle morphology for silicas having octadecylsilane content up to 0.6 mmol g⁻¹. The supported catalysts presented activity in ethylene polymerization in the range of 1100–1900 kg PE molZr⁻¹ h⁻¹ bar⁻¹. The surface polarity of the catalyst influenced the molar mass of the resulting polyethylene. The increase of the ODS content on the silica surface led to a supported catalyst with slower kinetic behavior in the gas phase, which might be attributed to the diffusive effects of the octadecyl layer on the catalyst surface.     

Optimization of olefin copolymerization: effects of reaction parameters on catalytic activity and properties

The copolymerization of ethylene with 1-hexene using Et[Ind]₂ZrCl₂/MAO as catalyst was studied by multivariate methods. Three complete factorial designs were performed to study the influence of 1-hexene concentration, reaction temperature and [Al]/[Zr] ratio on catalytic activity, copolymer viscosity, crystallinity and melting point. Since the [Al]/[Zr] ratio has a small effect on the catalytic activity, a fourth design with 1-hexene and temperature was developed, giving higher catalytic activities. Temperature and 1-hexene concentration were the main effects found in the system. A second order effect arising from 1-hexene versus [Al]/[Zr] ratio was also detected. Polymer viscosity, crystallinity and melting points decreased with 1-hexene concentration. Viscosity decreased with temperature whereas crystallinity increased when the temperature was raised from 30 to 60 °C. Received: 13 June 1997/Revised version: 2 November 1997/Accepted: 21 November 1997