Key Laboratory of Soft Matter Chemistry, Chinese Academy of Sciences, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, China.
Angew Chem Int Ed Engl. 2016 Oct 10;55(42):13281-13285. doi: 10.1002/anie.201607152.
The introduction of even a small amount of polar functional groups into polyolefins could excise great control over important material properties. As the most direct and economic strategy, the transition-metal-catalyzed copolymerization of olefins with polar, functionalized monomers represents one of the biggest challenges in this field. The presence of polar monomers usually dramatically reduces the catalytic activity and copolymer molecular weight (to the level of thousands or even hundreds Da), rendering the copolymerization process and the copolymer materials far from ideal for industrial applications. In this contribution, we demonstrate that these obstacles can be addressed through rational catalyst design. Copolymers with highly linear microstructures, high melting temperatures, and very high molecular weights (close to or above 1 000 000 Da) were generated. The direct synthesis of polar functionalized high-molecular-weight polyethylene was thus achieved.
即使在聚烯烃中引入少量的极性官能团,也可以极大地控制重要的材料性能。作为最直接和经济的策略,过渡金属催化烯烃与极性官能化单体共聚代表了该领域最大的挑战之一。极性单体的存在通常会显著降低催化活性和共聚物分子量(达到几千甚至几百道尔顿的水平),从而使共聚过程和共聚物材料远非理想,无法应用于工业。在本研究中,我们证明通过合理的催化剂设计可以克服这些障碍。生成了具有高度线性微观结构、高熔点和非常高分子量(接近或高于 1000000Da)的共聚物。因此,直接合成了极性官能化的高分子量聚乙烯。