【Ten Years of Great Progress in Chemical Technology】Initiation of single-center catalyst and polyolefin product development from 2025 to 2033
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This post was last edited by Desert Fish on 2023-9-23 at 10:32. Looking back at the ten-year development of chemical technology, let’s praise the prosperity and strength of modern China. This is just a starting point; more participation will make it more lively. Hainan Sea River becomes even better with you here. [Ten Years of Progress in Chemical Equipment] – A continuously updated summary thread; feel free to join the discussions: https://bbs.hcbbs.com/thread-3576046-1-1.html. Enhance quality awareness and promote high-quality development. ----------------------------------------- On September 14th, a major project of Sinopec, “Development of Single-Center Catalysts and Their Polyolefin Products,” led by the Beijing Research Institute of Chemical Technology, was launched in Beijing. Leveraging Sinopec’s advantages across the entire industry chain in polyolefin catalysts, production processes, and product development, this project brings together research institutions, manufacturing enterprises, universities, and leading companies in the industry to form a collaborative team for joint efforts. The goal is to overcome the barriers to the advanced development of China’s polyolefin industry, ensure the security of the industry chain and supply chain, and drive high-quality development in new chemical materials. Developing new technologies for single-center catalysts and resin products is an important approach to achieving self-sufficiency and control over the key technologies for high-end products. In recent years, the demand for single-center catalysts, represented by metallocene catalysts, as well as polyolefin products has increased rapidly. However, China still lacks the capacity for large-scale production; there is an urgent need to overcome the scientific challenges and technical difficulties related to the mechanism of action, structural design, synthesis, and application of single-center catalysts and their polyolefin products, in order to achieve self-sufficiency in key technologies. Since the 1990s, the North China Institute of Chemical Technology has been engaged in research and development of catalysts with single active centers. It was one of the first institutions in China to industrialize metallocene polyethylene catalysts. The institute conducts research on the main compounds that make up catalytic systems, as well as on carriers and co-catalysts. By combining its polymer research and development capabilities with its expertise in polymerization processes, analysis of polymer structure and properties, new product development, and polymer processing, it has established a fairly complete technical R&D framework. In this collaboration, 11 organizations from within and outside the industry cluster have joined forces: Beijing Institute of Chemical Technology, Sinopec (Guangdong) Refining & Chemical Co., Zhongyuan Petrochemical, Maoming Branch, Yangzi Petrochemical, Guangzhou Branch, Sino-Korea (Wuhan) Petrochemical, Shanghai Engineering Corporation, East China University of Science and Technology, Guangdong Zhonghe Plastics & Chemicals Co., Ltd., and Hangzhou Foster Applied Materials Co., Ltd. By covering the entire innovation chain from upstream to downstream, these entities will focus on areas such as fundamental research, catalyst development, product development, and applied research, striving to develop new single-center catalysts as well as new polyolefin products and grades. The goal is to address the challenge of achieving domestic production of high-end new single-center polyolefin materials that are urgently needed in fields such as healthcare, optics, automotive manufacturing, and packaging.
【Ten Years of Great Progress in Chemical Technology】264- The country’s first bio-based carbonate production line will go into operation by 2023 https://bbs.hcbbs.com/thread-5105350-1-1.html (Source: Haichuan Chemical Industry Forum)
Catalysts are regarded as the “chips” of the chemical industry, as they can improve the efficiency of chemical reactions and enable large-scale production. Chemical synthesis, petrochemical refining, and environmental treatment are its three main application areas. Traditional EPDM production initially used vanadium-based catalysts, which had drawbacks such as low activity, short lifespan, high toxicity, and dark polymer color, and have since been phased out. Currently, titanium-based catalysts are most commonly used in EPDM production; although they are highly active, they tend to produce long ethylene chains that lead to crystallization, thereby affecting the properties of the rubber. Metallocene catalysts possess advantages that traditional vanadium- and titanium-based catalysts cannot match: they have higher catalytic activity. Metallocene catalysts are homogeneous catalysts, with each molecule of their active center dissolved in the solvent, which gives them high activity. Its activity can reach hundreds or even thousands of times that of traditional Ziegler–Natta and Phillips catalysts. For example, at 70°C, the dibenzofulvenyl zirconium complex (C13H8-C2H4-C13H8)ZrCl2 containing 1 gram of zirconium can produce 3×10^5 kg of polyethylene under the activation of a co-catalyst. Such high catalytic activity allows for a **reduction in the amount of catalyst used in industrial production; moreover, the low ash content of this catalyst means that it can be permitted to remain in polyolefin products.
Single-active-center metallocene catalysts are homogeneous catalysts, also known as single-site catalysts, and possess a single catalytic active center. As an olefin catalyst, its catalytic active center is situated in a constrained coordination environment that allows only monomers to coordinate to the catalyst’s active sites; as a result, it enables precise control over the molecular weight of the polymer, the molecular weight distribution, the content of copolymer monomers, and the distribution of polymer fragments along the main polymer chain, among other things. The molecular weight distribution (Mw/Mn≈2) of polymers produced using metallocene catalysts is narrower than that of polymers obtained with multi-center catalysts (Mw/Mn=3–8). Moreover, the distribution of the comonomers in the polymer backbone is relatively uniform, with long and short side chains arranged regularly along the main polymer chain. These parameters enable the new polymer material to have new applications (such as mLLDPE), thereby expanding its market prospects. It can effectively regulate the microstructure of polymers. By modifying the electronic effects and spatial structure of ligands containing cyclopentadienyl (Cp) groups, it is possible to design and synthesize a wide range of metallocene complexes with different structural types. This modifying effect can **alter the catalytic activity of the catalyst, and it can also affect certain properties of the resulting polymer, such as molecular weight and the content of comonomers. Moreover, metallocene catalysts with certain symmetrical elements can also achieve stereoselective control over olefin polymerization, enabling the production of polyolefin materials with specific stereoselectivity from chiral olefins, such as isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene, semisynthetic polypropylene, stereoblock polypropylene, and syndiotactic polystyrene. The polyolefins with the desired stereoregularity obtained can exhibit unique properties, thereby enabling them to be used in a variety of applications. Therefore, by controlling the polymerization conditions and modifying the molecular structure of the catalyst, polymers suitable for various market demands can be easily obtained.
Excellent copolymerization properties: Metallocene catalysts can catalyze the copolymerization of ethylene with many comonomers, and more than 50 such comonomers have been reported to date. Other studies have found that, in addition to the common α-olefins, norbornene, and styrene, monomers that can undergo copolymerization can also include conjugated dienes and polar monomers. Therefore, metallocene catalysts can be used to produce a variety of new polyolefin products; these diverse products, with their excellent properties, can be widely applied in various fields of production and daily life. Applications of metallocene catalysts: Metallocene catalysts have a wide range of applications; they can be used to produce metallocene polyethylene (mPE), metallocene polypropylene, metallocene syndiotactic polystyrene, metallocene cycloolefins, and more. Many well-known materials today, such as high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ultra-low density polyethylene, and so on, were also derived from this.
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