最新刊期
卷 25 ， 期 4 ， 2012
- 摘要：Polyethylene is the most widely used synthetic resin in China, which is used to produce films, cables, injection products, coatings, fibers and tubes. In recent years, polyethylene industry developed rapidly in China. However, high added value products are unable to meet growing domestic demand, which need a great deal of import, such as bimodal polyethylene. Bimodal polyethylene is a special resin with a good balance between processability and mechanical properties, which has been one of the most promising high performance polyolefin. In this article, structure and properties and production process of bimodal polyethylene were reviewed. Regulation methods of bimodal polyethylene product were briefly introduced.关键词：Bimodal polyethylene;Production process;Regulation methods
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发布时间：2022-09-18 - 摘要：As one important type of synthetic rubber, liquid rubber can flow at room temperature. The performance characteristics and classification of liquid rubber are introduced. And the structure, performance characteristics and main use of liquid diene rubber which are liquid butadiene rubber, liquid nitrile rubbe, liquid isoprene rubber, liquid butadiene-sytrene rubber and liquid chloroprene rubber are emphatically elaborated. Then the development of research, production and usage are reviewed. Because liquid rubber is convenient to realize continuous production and automation, and convenient processing, it comply with the trend of "low carbon". Then suggestions for the development of liquid rubber are put forward from product to application.关键词：Liquid rubber;Diene;Structure characteristics;Research
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发布时间：2022-09-18 - 摘要：The immobolization technology and the selection of carrier of homogeneous Zeigler-Natta and metallocene catalysts were introduced. The major factors of carrier selection depend on strength, density, total pore volume, pore distribution, pore size, particle size and shape, and other physical properties of the carrier. The structure and performance characteristics of silica gel as polyolefin catalysts support were also reviewed, and the synthesis mechanism and influence factors in the process of silica gel preparation were introduced in details. The silica gel prepared have typical properties with specific surface area ranged from 280 m2/g to 320m2/g, bulk density 0.28-0.32g/cm3, porosity volume 1.40-1.70 cm3/g and average pore diameter 18-22 nm. Research on silica gel with different properties (such as smaller particle size and modified silica gel, etc.) for special requirements of catalysts was proposed.关键词：Immobolization of homogeneous catalyst;Silica gel;Metallocene catalyst;Modification
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发布时间：2022-09-18 - 摘要：With the constant development of plastic industry, medical science and biological technology, and our focus on healthy day by day, medical plastics are widely used. Because of its security and innocuity, more and more polyolefin are used for medical use. So far, polyvinylchloride (PVC) are still used as medical material in our country. However, substituting other polyolefin for PVC material is an important research direction in medical polyolefin filed for our concern on human healthy and environmental safety. This paper reviewed the development of research and application of medical polyolefin. The typical characterization and application of medical polyolefin was summarized. The development of research and application of all kinds of medical polyolefin was introduced in detail, and some possible topics of medical polyolefin in the future were also discussed.关键词：Medical Polyolefin;Research;Application
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发布时间：2022-09-18 - 摘要：The excellent optical and mechanical properties of transparent polypropylene were taken more attention by researchers. In this paper, study on preparation technology of transparent PP was introduced, including the nucleating agent technology, random copolymer, metallocene catalysis and blend.At present, it is a main technology of the preparation of transparent PP that catalyzed by Ziegler-Nata copolymer PP and added a nucleating agent, catalyzed by metallocene PP for the ideals of transparent material. Meanwhile, some possible topics of transparent polypropylene process technologies were discussed.关键词：Polypropylene;Transparent;Nucleator
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发布时间：2022-09-18 - 摘要：This paper reviewed the development of polyolefin catalyst, which finds wide applications in polyethylene and polypropylene copolymerization of polyolefin industry, and focused on the research methods and applications of the Ziegler-Natta catalysts, metallocene catalysts, chromium catalysts, late transition metal catalysts, and other complex catalyst. Then, the researching trends of the Ziegler-Natta catalysts were introduced and the status of domestic polyolefin catalyst research and application were summarized. While the polymerization process and research status of the different new products of polyethylene and polypropylene were discussed, the structural performance and applications of new products were highlighted. Finally, some possible topics of polyolefin industry in the future were also discussed. In the end, some suggestions on domestic polyolefin development were given.关键词：Polyolefin;Ziegler-Natta catalyst;Metallocene catalyst;New product
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发布时间：2022-09-18 - 摘要：Polyethylene with bimodal molecular weight distribution, having a good balance between mechanics and processibility, is one of polyethylene development directions. In this paper, slurry processes such as Hostalen, CX and Innovene-S for polyethylene with bimodal molecular weight distribution were explained. The advantages and disadvantages of these slurry processes were summarized for comparison, and some suggestion were given for the plant installation in China. Besides, the developments on catalyst for theses three processes were reviewed in the paper. The performance of the related catalysts was explained, suggesting that the catalyst must be suited to the related slurry process. On the development of catalyst in China, some advices were proposed.关键词：Bimodal;HDPE;Polymerization process;Catalyst
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发布时间：2022-09-18 - 摘要：In this paper, we reviewed the development process for polypropylene catalysts, which is divided into several important periods. In addition, this comments concentrated on two types of catalysts (i.e. the single-and the multi-site catalysts) and three kinds of catalysts (i.e. Ziegler-Natta, metallocene and late-transition iron metal catalysts). We also introduced the polymerization mechanism of the above catalysts.关键词：Single-and multi-site;Ziegler-Natta catalyst;Metallocene catalyst;Late-transition metal catalyst;Propylene polymerization mechanism
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发布时间：2022-09-18 - 摘要：MgCl2-supported Ziegler-Natta catalyst is currently the most widely used industrial polyolefin catalyst. The catalyst is highly active and can produce morphology-controlled polymer. The MgCl2 support is one of the main components of such catalyst and has an important role in the research of supported Ziegler-Natta catalyst. The MgCl2 support preparation is one of the key technologies of the catalyst production. In this article, the development of early supported Ziegler-Natta catalyst and the structural features of MgCl2 as support for Ziegler-Natta catalyst are briefly introduced, with emphasis on the activation and morphology control technologies for preparing MgCl2 support (in particular, spherical MgCl2 support).关键词：Ziegler-Natta Catalyst;MgCl2;Support
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发布时间：2022-09-18 - 摘要：High-pressure polyethylene pipe resins are mainly be produced to water pipes, gas pipes and a variety of industrial pipes, which special resins with high technology and good market prospect. Most of the high pressure-resistance polyethylene pipe resins have bimodal or multimodal molecular weight distribution, and the polymerizations are often be carried out in double or multiple series reactors with metallocene or Z-N catalyst which is with good copolymerization performance. The paper mainly describes the molecular structure, properties, catalyst and techniques of high-pressure polyethylene pipe resins, and provides a review of domestic catalysts and preparation technologies.关键词：High-pressure;Polyolefin;Pipe;Twin peaks
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发布时间：2022-09-18 - 摘要：Syndiotactic polypropylene possesses unique structure and appears well at transparency, permeability, radiation resistance and so on. The blends, based on syndiotactic polypropylene, have great potential uses in medical products, package materials and automobile accessories. In order to get good commercial syndiotactic polypropylene,researches which are focused on catalyst selectivity, catalyst supporting, polymerization process and so forth need deeply carry out. In this paper, syndiotactic metallocene catalysts and corresponding polypropylene products are reviewed. The development of syndiotactic metallocene catalysts and the relationship between their structures and properties are mainly discussed. The polymerization process, used in industrial production of syndiotactic polypropylene is introduced as well. Besides, the applications of syndiotactic polypropylene are summarized.关键词：Metallocene;Syndiotactic polymers;Polypropylene;Review
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发布时间：2022-09-18 - 摘要：High crystallinity Polypropylene (HCPP) typically can be prepared by adding nucleating agent to high isotacticity PP (HIPP). In this paper, the catalyst systems and catalyst preparation techniques of high crystallinity polypropene (HCPP) were reviewed in details. HIPP can be prepared by via of matching the conventional Ziegler-Natta catalyst with suitable electron donors and choosing suitable metallocene complexes. Presently the conventional Z-N catalysts are mainly used in the PP production process. The manufacturers, grades of HCPP, and the major polymerization processes of HCPP such as Speripol loop/gas-phase polymerization process, Unipol gas-phase polymerization process, Novolen gas-phase polymerization process and Hypol bulk polymerization processes, etc. were introduced. The application prospects of HCPP were also introduced. Preparation of HCPP is one of the crucial ways to develop new grades PP and high-performance PP, and HCPP has great market potential. Therefore, it will play a significant role in domestic HCPP production.关键词：High crystallinity PP;Z-N catalyst;Metallocene catalyst;Polymerization process
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发布时间：2022-09-18 - 摘要：This paper discussed Solution and Gas phase method production processes and Catalysts of polyethylene with 1-octene as comonomer in foreign large powerful companies such as DOW and NOVA and DSM and Chevron Phillips. Introduced the properties and functions of ethylene/1-octene copolymer such as the full density polyethylene film, rotational molding and injection molding resin. The properties and applications of heat-resistant reinforced polyethylene PE-RT resin and plastic olefin elastomer POE resin were also introduced.Finally,development and future prospects of ethylene/1-octene copolymer were discussed.While suggestions for the actuality of our country in process and applications of ethylene/1-octene progress were put forwarded.关键词：1-Octene;Comonomer;Ethylene/1-Octene Copolymer;PE-RT;POE
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发布时间：2022-09-18 - 摘要：Technology for branched polyethylene by metallocene catalysts was one of the most important advancements in polyolefin industry. Metallocene LLDPE was widely used in film and heavy duty packaging due to its high performance of anti-pierce and anti-impact. The property of m-LLDPE was highly related to the type, concentration and the distribution of comonomer incorporated. This review introduced the originality of the molecular heterogeneity in m-LLDPE from the point view of catalytic active center and the effect of the fluctuation in polymerization conditions. Method for molecular heterogeniety characterization in branched polyethylene by 13C NMR, TREF and DSC-SSA were discussed in detail to show the difference of the comonomer sequence composition, distribution and crystallization properties of the copolymers.关键词：Heterogeneity of branching;13C NMR;TREF;DSC-SSA
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发布时间：2022-09-18 - 摘要：β-Form nucleating agent used in polypropylene (PP), gives the PP products excellent impact, heat distortion and high porosity. This paper reviews the development advances in polypropylene β-form nucleating agent in recent years. It focuses on the role, sorts, strengths and weaknesses of β-form nucleating agent, and proposes what need to be resolved in the future development of β-form nucleating agents.关键词：Polypropylene;β-Form;Nucleating agent
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发布时间：2022-09-18 - 摘要：Polypropylene blends and copolymers show a complicated morphology,the study in morphologic structure, compatibility, and phase separation is the main topic in this field. Compared with common methods (DSC, DMA), the dynamic rheological research possesses unique advantages, and is very sensitive to the formation and evolution of the morphology. Based on the basis theory of dynamic rheological,the latest development of using dynamic rheological measurements for researching the morphologic structure, compatibility, and phase separation of polypropylene and its blends/copolymers was emphatically introduced and evaluated in this paper. The dynamic rheological measurements were demonstrated as an effective method for the morphologic structure, compatibility, and phase separation characterization of polypropylene and its blends/copolymers.关键词：Polypropylene;dynamic rheology;Terminal range;Time-temperature superposition principle
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发布时间：2022-09-18 - 摘要：Spherical MgCl2-supported Ziegler-Natta catalyst is one of the most widely used industrial polyolefin catalysts. The property of such catalyst is intensively influenced by the preparation technology, so the preparation process is important to research. In this paper, the spherical polyolefin catalyst was prepared by the reaction of spherical MgCl2 support with TiCl4.The Ti content, specific surface area, specific pore volume and crystalline form of intermediates in the reaction process were analyzed. The effect of dibutyl phthalate as internal donor in such process was also investigated. The result of this experiment provided an important reference for the preparation of spherical MgCl2-supported Ziegler-Natta catalyst.关键词：Spherical MgCl2 support;TiCl4;Dibutyl phthalate
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发布时间：2022-09-18 - 摘要：Three novel catalyst systems which were composed by PNP ligands/Ti(IV)/methylaluminoxane (MAO) has been synthesized, and the ligand and catalyst structure has been characterized by NMR, elemental analysis and mass spectrometry.The catalyst performance which showed during ethylene oligomerization test indicate: the titanium-based catalyst activity could be up to 2.58×105g/ (molTi·h), the selectivity of α-olefin such as 1-butene, 1-hexene, and 1-decene is 80.72%.关键词：Ethylene oligomerisation;Ti (IV) based catalyst;PNP ligand;Linearα-olefin;Copolymer
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发布时间：2022-09-18 - 摘要：Ultra high molecular weight polyethylene (UHMWPE) is one of the best engineering plastics.Comparing with the other polymeric materials,UHMWPE has a variety of special performances,such as impact resistance,abrasion resistance,chemical resistance,low-temperature resistance,stress cracking resistance,anti-adhesion ability,excellent electrical insulation,self-lubricating property,safety and health and so on.UHMWPE is widely used in the sports,textile,mining,chemical industry,packaging,architectural,mechanical,electrical,medical and other fields instead of carbon steel,stainless steel and bronze.In this paper,the present domestic production status,demand,product processing and applications of UHMWPE were summarized,and the development prospects of UHMWPE in the future were predicted.关键词：Ultra high molecular weight polyethylene;Technology;Manufacturer;Application.
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发布时间：2022-09-18 - 摘要：First,environmental regulations about emulsion styrene-butadiene rubber(ESBR) at home and abroad are introduced,such as EU REACH,tire labeling regulation and the United States national fuel efficiency policy.Second,the structure characteristics of ESBR are elaborated,then environmental protection mechanisms of green oil-extended and its on the role of ESBR are explained.Third,the role of accessory ingredient such as initiator,terminator,accelerator and antiager and their developments are overviewed.And the classification and developments of oil-extended are elaborated.Furthermore,main trademarks and products of green ESBR is reviewed.Last,suggestions for the development of green ESBR from accessory ingredient,oil-extended to products are put forward.关键词：Environmental;Emulsion styrene-butadiene rubber;Accessory ingredient;Oil-extended
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发布时间：2022-09-18 - 摘要：Polypropylene process is summarized,including the Spheripol technology of Lyondell basell Industtries,the HypolⅡ technology of Prime Polymer,the Borstar technology of Borealis Corporation, the Innovene technology of Ineos Corporation,the Unipol technology of Dow Corporation,the Novolen technology of NTH Corporation,the Spherizone technology of Lyondell Basell Corporation,the Horizone technology of Japan Polyproylene Corporation and the Sumitomo process of Sumitomo chemical company,from the aspects of technical characteristics,catalyst,reaction conditions and product features.The situation of polypropylene process in China is analyzed,and corresponding suggestions are proposed.关键词：Polypropylene;Process;Technical progress
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发布时间：2022-09-18
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