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Access to Disentangled Ultrahigh Molecular Weight Polyethylene via a Binuclear Synergic Effect |
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| Authors: | Zhen Zhang Xiaohui Kang Yang Jiang Zhongyi Cai Shihui Li Prof. Dongmei Cui |
| Affiliation: | 1. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022 Changchun, China Department of Materials Science and Engineering, Jilin University, 130022 Changchun, China These authors contributed equally to this work.;2. College of Pharmacy, Dalian Medical University, 116044 Dalian, China These authors contributed equally to this work.;3. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022 Changchun, China School of Applied Chemistry and Engineering, University of Science and Technology of China, 230026 Hefei, China;4. Department of Materials Science and Engineering, Jilin University, 130022 Changchun, China;5. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022 Changchun, China |
| Abstract: | Disentangled ultrahigh molecular weight polyethylene (dis-UHMWPE) has excellent processability but can be achieved under extreme conditions. Herein, we report ethylene polymerization with the binuclear half-sandwich scandium complexes C1-Sc2 and C2-Sc2 to afford UHMWPE . C1-Sc2 bearing a short linker shows higher activity and gives higher molecular weight PEs than C2-Sc2 containing a flexible spacer and the mononuclear Sc1 . Strikingly, all UHMWPEs isolated from C1-Sc2 under broad temperature range (25–120 °C) and wide ethylene pressures (2–13 bar) feature very low degree of entanglement as proved by rheological test, DSC annealing study and SEM. These dis-UHMWPEs are facilely mediated solid-state-process at 130 °C and their tensile strength and modulus reach up to 149.2 MPa and 1.5 GPa, respectively. DFT simulations reveal that the formation of dis-UHMWPE is attributed to the binuclear synergic effect and the agostic interaction between the active center and the growing chain. |
| Keywords: | Binuclear Complex Coordination Polymerization dis-UHMWPE Rare-Earth Metal Synergic Effect |