气相法聚乙烯BCG-Ⅱ型催化剂的开发和应用

对气相法聚乙烯BCG-Ⅱ型催化剂的组成、粒径分布及催化剂的淤浆聚合性能进行了研究。研究结果表明，BCG—Ⅱ型催化剂的活性较高，聚合物堆密度适中，应用在Unipol乙烯气相聚合工艺装置上操作良好，所生产的树脂颗粒均匀。干爽且流动性好，产品质量合格、稳定。     

BCE催化剂制备双峰PE的研究

研究开发了BCE高效聚乙烯催化剂．并模拟超临界工艺制备出双峰聚乙烯树脂。BCE催化剂具有较高的活性（约为参考催化剂的2倍）和良好的氢调敏感性;与参考催化剂相比,该催化剂制备的聚乙烯树脂具有较高的堆积密度（0．39g／cm^3）和较窄的相对分子质量分布,重均分子量低于1000的部分较少。     

当今世界聚烯烃工业的重点技术

叙述和分析了９０年代以来世界聚烯烃工业的重点技术，包括高效催化剂技术，无溶剂聚合技术，气相流化床聚乙烯工艺的冷凝态进料技术，共聚技术，生产分子量双峰分布聚乙烯树脂技术以及不造粒技术。     

淤浆法聚乙烯催化剂的评价研究

齐格勒-纳塔(Ziegler-Natta)催化剂是目前世界广泛应用的聚乙烯催化剂,通过改性可以使其具有良好的氢调敏感性和共聚性能。作者考察了钛系淤浆法高密度聚乙烯催化剂的基本参数、粒径分布;通过催化剂的聚合评价实验,研究了它的氢调敏感性、共聚性能、聚合动力学曲线,及其聚合物的粒径分布,并探讨高密度聚乙烯催化剂的性能调整方向。     

中国专利

包含茂金属生产的树脂和铬生产的树脂的聚乙烯共混物的制备方法本发明涉及的均质聚乙烯的制备方法包括:a)在茂金属催化剂存在下,在反应器中生产第一聚乙烯树脂,该聚乙烯树脂具有0.942~0.970 g/cm3的密度和0.5~150.0 g/10 min的熔体流动速率(MFR),其中,MFR按照ASTM D 1238—2010在190℃,21.6kg的负荷条件下测试,密度按GB/T 1505—2010测试。b)在铬催化剂存在下,在反应器中单独生产第二聚乙烯树脂。c)将第一聚乙烯树脂和第二聚乙烯树脂物理共混生产均质聚乙烯,该均质聚乙烯至少包含质量分数为25%的第一聚乙烯树脂。     

气相法聚乙烯SCG-1催化剂的工业应用

介绍了气相法聚乙烯SCG－1催化剂的评价结果和工业应用情况，并与进口催化剂所生产的薄膜产品性能进行了对比。结果表明，用SCG－1催化剂生产中、低密度产品时，催化剂实际活性分别为9和8kg/kg。用SCG－1催化剂生产的树脂产品颗粒分布均匀，产品质量良好，均为优等品，特别是薄膜产品的雾度和外观等级较进口催化剂生产的薄膜产品好。     

新型聚乙烯催化剂的性能研究

对一种采用球型载体合成的聚乙烯催化剂的性能进行研究。该催化剂的性能良好，具有一定工业应用前景。     

NT-1催化剂在淤浆法HDPE生产中的工业试用

介绍了国产NT-1催化剂在淤浆法高密度聚乙烯装置上首次工业化应用试验的情况,并将该催化剂的性能特点与其他催化剂进行了对比。工业试用结果表明,NT-1催化剂活性高、氢调敏感性好、聚合物细粉少,粒径分布集中。所生产的高密度聚乙烯产品达到优级品。     

铬/钒双金属催化剂催化乙烯气相聚合

在实验室小试气相聚合釜中对铬/钒双金属催化剂进行乙烯聚合评价,考察了不同聚合温度和压力时催化剂的性能,研究了不同条件下催化剂的动力学行为,并将其聚合动力学曲线与用工业铬系催化剂的进行了比较。结果表明:随着聚合温度升高,用铬/钒双金属催化剂制备的聚乙烯的相对分子质量减小,熔体流动速率增大,在所研究聚合温度范围内铬/钒双金属催化剂对温度更敏感;随着聚合压力增大,催化剂活性显著提高,聚乙烯相对分子质量增加;聚合动力学曲线与铬系催化剂不同,聚合反应速率先增大再降低最后逐渐达到平稳。     

聚乙烯催化剂在扬子公司工业应用成功

中国石化集团公司石油化工科学研究院研制开发的NT-1高效聚乙烯催化剂，最近在扬子石化公司7万t／a浆液法聚乙烯装置上成功进行了工业应用试验，共生产HDPE 7000F和5000S两个牌号的树脂约1500t。NT-1高效聚乙烯催化剂在工业应用过程中产品牌号切换与生产过程平稳、工艺控制稳定。与国产同类催化剂相比，NT-1高效聚乙烯催化剂具有活性高、     

薄膜用高性能LLDPE树脂的开发

采用气相流化床工艺,使用钛系催化剂,以1-己烯作共聚单体,采用连续不停车切换生产薄膜用高性能线型低密度聚乙烯树脂。测试结果表明:树脂的各项性能良好,薄膜的落镖冲击破损质量达92 g;拉伸断裂应力达31.7 MPa;拉伸断裂应变达1 183%。     

SCG-1系列催化剂在茂名乙烯全密度聚乙烯装置上的应用

通过介绍SCG-1系列催化剂在茂名全密度聚乙烯装置中的应用历程,分析、对比SCG-1系列催化剂和进口催化剂在装置上的应用情况,包括催化剂的主要性能指标、催化剂在反应器中的表现,以及生产的产品种类和质量等,表明使用SCG-1系列催化剂,生产操作平稳,产品质量合格,各项性能指标等同或优于进口催化剂,已经在LLDPE装置上得到了大量的应用。     

Processability and mechanical properties for binary blends of PP and LLDPE produced by metallocene catalyst

Processability at extrusion coating and mechanical properties of the films obtained are investigated by means of linear and nonlinear rheological measurements and tensile tests for blends of polypropylene (PP) and linear low‐density polyethylene (LLDPE). Both materials are produced by metallocene catalyst. The processability of PP is found to be improved by the addition of LLDPE; the blend shows low level of motor torque and head pressure in an extruder and small level of neck‐in as compared with pure PP. Further, the anisotropy of ultimate tensile strength, which is prominent for PP, is reduced by blending with LLDPE. As a result, the blend having 20 wt % of LLDPE shows appropriate properties in the molten state for extrusion coating and in the solid state as a film. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Fractionation and Characterization of a Lldpe Synthesized by a Metallocene Catalyst

A commercial, linear, low-density polyethylene (LLDPE) synthesized by a metallocene catalyst was analyzed by temperature-rising elution fractionation, Fourier transform infrared, and ¹³C-nuclear magnetic resonance spectroscopy. It was found that the LLDPE sample is mainly butyl branch. The degree of branching decreased with increasing elution temperature. The results from wide-angle x-ray diffraction and size exclusion chromatography confirmed that the fractionation was based on the ability of fractions to crystallize rather than molecular weight. The LLDPE sample has a narrow molecular-weight distribution.     

Copolymerization of ethylene and in situ‐generated α‐olefins to high‐performance linear low‐density polyethylene with a two‐catalyst system supported on mesoporous molecular sieves

The manufacture of linear low‐density polyethylene (LLDPE) is of great significance in academia and industry. The employment of a single monomer, i.e. ethylene, to produce LLDPE by introducing two catalysts into one reactor to conduct ethylene copolymerization with in situ‐generated α‐olefins has proved to be an effective way in this case. Moreover, immobilization of catalysts affords LLDPE with better morphology and improved physical properties. An iron‐based diimine complex immobilized on methylaluminoxane (MAO)‐treated mesoporous molecular sieves was used to oligomerize ethylene to α‐olefins with improved selectivity to lower molar mass fractions. Based on this, zirconocene compound was also supported on mesoporous molecular sieves to comprise a two‐catalyst system to produce LLDPE from a single ethylene monomer. Copolymerization performed at both atmospheric and high pressure produced LLDPE of high molecular weight and broad molecular weight distribution without using MAO during the polymerization processes. Physical and mechanical measurements evidenced significant increases in tensile strength, tensile modulus and Izod impact strength. A marked shear‐thinning phenomenon and improved storage modulus of LLDPE produced using catalysts supported on MCM‐41 and SBA‐15 mesoporous molecular sieves indicated a stronger interfacial interaction between the molecular sieve support and the polymeric matrix. Copyright © 2010 Society of Chemical Industry     

LLDPE电缆料TJDL-9270的开发

介绍了线型低密度聚乙烯(LLDPE)电缆料TJDL-9270的性能特点和开发过程。根据电线电缆应用对树脂加工和机械性能的要求,确定了产品指标和生产技术路线及反应条件。分析了F催化剂产品的生产难点。提出了产品切换过程的关键控制要素。研制的TJDL-9270相对分子质量分布宽,易于加工,产品质量稳定,表面光洁度高,并具有优异的机械性能和耐环境应力开裂性能,完全适应高速电缆料的挤出应用。     

Reactive compatibilization of LLDPE/PS blends with a new type of Lewis acid as catalyst

The reactive compatibilization of LLDPE/PS (50/50 wt%) was achieved by Friedel–Crafts alkylation reaction with a combined Lewis acids (Me₃SiCl and InCl₃·4H₂O) as catalyst. The graft copolymer at the interface was characterized by Fourier transform infrared spectroscopy and the morphology of the blends was analysized by scanning electron microscopy. It was found that the combined Lewis acids had catalytic effect on Friedel–Crafts alkylation reaction between LLDPE and PS, and the catalytic effect was maximal when the molar ratio of InCl₃·4H₂O to Me₃SiCl was 1:5. The graft copolymer LLDPE–g–PS was formed via the F–C reaction and worked as a tailor-made compatibilizer to reduce the interfacial tension. The mechanical properties of reactive blend with combined Lewis acids as catalyst was notably improved compared to that of physical LLDPE/PS blend and serious degradation had been decreased compared to the reactive blend system with AlCl₃ as catalyst; we interpreted the above results in term of acidity of combined Lewis acids.     

气相法mPE的性能剖析

茂金属聚乙烯（mPE)具有优越的力学性能和光学性能，这与茂金属催化剂的催化性能及其聚合物特殊的链结构形式密切相关。对国内开发的mPE进行了结构表征，结果表明：mPE薄膜的力学性能和光学性能明显优于线型低密度聚乙烯产品，其耐穿刺性能明显好于其他聚乙烯产品。     

LLDPE装置负荷波动对反应系统的影响及措施

针对气相法线型低密度聚乙烯(LLDPE)装置的生产特点,分析指出生产负荷波动的主要原因有:催化剂、原料组分、反应温度控制参数以及与反应相关的其他系统设备故障的影响。并提出相应措施:控制催化剂活性、控制催化剂的加入量、优化反应温度的控制参数。从而确保了气相法LLDPE装置的平稳运行。     

Effect of blending high‐pressure low‐density polyethylene on the crystallization kinetics of linear low‐density polyethylene

It is well known that the addition of a small amount of high‐pressure low‐density polyethylene (HP‐LDPE) to linear low‐density polyethylene (LLDPE) can improve the optical properties of LLDPE, and LLDPE/HP‐LDPE blend is widely applied to various uses in the field of film. The optical haziness of polyethylene blown films, as a result of surface irregularities, is thought to be as a consequence of the different crystallization mechanisms. However, not much effort has been directed toward understanding the effect of HP‐LDPE blending on the overall crystallization kinetics (k) of LLDPE including nucleation rate (n) and crystal lateral growth rate (v). In this study, we investigated the effect of blending 20% HP‐LDPE on the crystallization kinetics of LLDPE polymerized by Ziegler‐Natta catalyst with comonomer of 1‐butene. Furthermore, by combining depolarized light intensity measurement (DLIM) and small‐angle laser light scattering (SALLS), we have established a methodology to estimate the lateral growth rate at lower crystallization temperatures, in which direct measurement of lateral growth by polarized optical microscopy (POM) is impossible due to the formation of extremely small spherulites. This investigation revealed that HP‐LDPE blending leads to enhanced nucleation rate, reduced crystal lateral growth rate, and a slight increase in the overall crystallization kinetics of pure LLDPE. From the estimated crystal lateral growth rate, it was found that the suppression in v from HP‐LDPE blending is larger at lower temperatures than at higher temperatures. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007