【Frontiers in HaiChuan Chemical Technology】Dalian University of Technology and Zhenhai Refining & Chemical Co. have achieved significant technical breakthroughs in the synthesis of key monomers for polyolefins

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Dalian University of Technology announced that recently, a research team led by Professor Liang Changhai from the School of Chemical Engineering at the university, in collaboration with Sinopec Zhenhai Refining & Chemical Co., successfully produced 4-methyl-1-pentene (4M1P) – a high-quality product – for the first time using a 100-ton-scale propylene dimerization test facility. This achievement marks a significant technical breakthrough in China’s field of synthesizing such high-end specialty monomers. Currently, 4M1P is primarily prepared through the dimerization of propylene, a highly exothermic reaction with a complex product distribution and high spontaneity. To achieve the efficient and directional conversion of propylene into the target product 4M1P, it is crucial to precisely control the catalyst and process conditions. At the beginning of 2018, a research team led by Professor Liang Changhai collaborated with Sinopec Zhenhai Refining & Chemical to carry out systematic research efforts. Starting with laboratory-scale experiments in batch reactors, they gradually moved on to scaling up the process using continuous reactors, and ultimately developed a pilot plant capable of handling hundreds of tons per batch, thus completing the entire journey from basic research to practical application. The research team overcame a series of challenges, including the difficulties associated with scaling up catalyst production from gram levels to kilogram levels, the safe transportation of materials, and the selection of appropriate process equipment. Through years of continuous research and development, along with numerous experiments and optimizations, they succeeded in developing an efficient catalyst that enabled the selective synthesis of 4M1P from 17 possible reaction pathways. The purity of the resulting product reached 99.3%, with key performance indicators exceeding those of imported similar products, thus achieving high-quality domestic substitution. It is reported that 4M1P is an important branched α-olefin; it can self-polymerize to form poly4-methyl-1-pentene (PMP), and it can also be used as a comonomer in high-quality linear low-density polyethylene (LLDPE), thereby significantly improving its toughness and optical properties. Among them, PMP is currently the thermoplastic resin with the lowest known density. It boasts a high melting point, excellent heat resistance, high transparency, good dielectric properties, and resistance to chemical corrosion. Thus, it has broad application prospects in fields such as electronics, optical instruments, high-end medical devices, and special packaging. However, the global production capacity for 4M1P is highly concentrated among a few foreign companies, resulting in a monopolistic situation. The successful independent synthesis of 4M1P not only lays a crucial foundation for China to reduce its reliance on imported materials for core components of high-end medical equipment (such as ECMO “artificial lungs”), but also provides reliable, domestically produced high-performance materials for strategic emerging industries like 5G communications and flexible electronics.