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Zhu B, Liu K, Luo L, Zhang Z, Xiao Y, Sun M, Jie S, Wang WJ, Hu J, Shi S, Wang Q, Li BG, Liu P. Covalent Organic Framework-Supported Metallocene for Ethylene Polymerization. Chemistry 2023; 29:e202300913. [PMID: 37341127 DOI: 10.1002/chem.202300913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 06/21/2023] [Accepted: 06/21/2023] [Indexed: 06/22/2023]
Abstract
The loading of homogeneous catalysts with support can dramatically improve their performance in olefin polymerization. However, the challenge lies in the development of supported catalysts with well-defined pore structures and good compatibility to achieve high catalytic activity and product performance. Herein, we report the use of an emergent class of porous material-covalent organic framework material (COF) as a carrier to support metallocene catalyst-Cp2 ZrCl2 for ethylene polymerization. The COF-supported catalyst demonstrates a higher catalytic activity of 31.1×106 g mol-1 h-1 at 140 °C, compared with 11.2×106 g mol-1 h-1 for the homogenous one. The resulting polyethylene (PE) products possess higher weight-average molecular weight (Mw ) and narrower molecular weight distribution (Ð) after COF supporting, that is, Mw increases from 160 to 308 kDa and Ð drops from 3.3 to 2.2. The melting point (Tm ) is also increased by up to 5.2 °C. Moreover, the PE product possesses a characteristic filamentous microstructure and demonstrates an increased tensile strength from 19.0 to 30.7 MPa and elongation at break from 350 to 1400 % after catalyst loading. We believe that the use of COF carriers will facilitate the future development of supported catalysts for highly efficient olefin polymerization and high-performance polyolefins.
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Affiliation(s)
- Bangban Zhu
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering Zhejiang University, Hangzhou, 310027, P. R. China
| | - Kan Liu
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering Zhejiang University, Hangzhou, 310027, P. R. China
| | - Liqiong Luo
- National-Certified Enterprise Technology Center, Kingfa Science and Technology Co., Ltd., Guangzhou, 510663, P. R. China
| | - Ziyang Zhang
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering Zhejiang University, Hangzhou, 310027, P. R. China
- Institute of Zhejiang University - Quzhou, 99 Zheda Rd, Quzhou, 324000, P. R. China
| | - Yangke Xiao
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering Zhejiang University, Hangzhou, 310027, P. R. China
| | - Minghao Sun
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering Zhejiang University, Hangzhou, 310027, P. R. China
| | - Suyun Jie
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering Zhejiang University, Hangzhou, 310027, P. R. China
| | - Wen-Jun Wang
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering Zhejiang University, Hangzhou, 310027, P. R. China
- Institute of Zhejiang University - Quzhou, 99 Zheda Rd, Quzhou, 324000, P. R. China
| | - Jijiang Hu
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering Zhejiang University, Hangzhou, 310027, P. R. China
| | - Shengbin Shi
- Institute of Zhejiang University - Quzhou, 99 Zheda Rd, Quzhou, 324000, P. R. China
| | - Qingyue Wang
- Institute of Zhejiang University - Quzhou, 99 Zheda Rd, Quzhou, 324000, P. R. China
| | - Bo-Geng Li
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering Zhejiang University, Hangzhou, 310027, P. R. China
| | - Pingwei Liu
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering Zhejiang University, Hangzhou, 310027, P. R. China
- Institute of Zhejiang University - Quzhou, 99 Zheda Rd, Quzhou, 324000, P. R. China
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Mao A, Chen J, Bu X, Tian L, Gao W, Saiz E, Bai H. Bamboo-Inspired Structurally Efficient Materials with a Large Continuous Gradient. Small 2023; 19:e2301144. [PMID: 37186449 DOI: 10.1002/smll.202301144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/10/2023] [Indexed: 05/17/2023]
Abstract
Because of its light weight and high strength, bamboo is used in many applications around the world. Natural bamboo is built from fiber-reinforced material and exhibits a porous graded architecture that provides its remarkable mechanical performance. This porosity gradient is generated through the unique distribution of densified vascular bundles. Scientists and engineers have been trying to mimic this architecture for a very long time with much of the work focusing on the effect of fiber reinforcement. However, there still lacks quantitative studies on the role of pore gradient design on mechanical properties, in part because the fabrication of bamboo-inspired graded materials is challenging. Here, the steep and continuous porosity gradient through an ingenious cellular design in Moso bamboo is revealed. The effect of gradient design on the mechanical performance is systematically studied by using 3D-printed models. The results show that not only the magnitude of gradient but also its continuity have a significant effect. By introducing a continuous and large gradient, the maximum flexural load and energy absorption capability can be increased by 40% and 110% when comparing to the structure without gradient. These bamboo-inspired cellular architectures can offer efficient solutions for the design of damage tolerant engineering structures.
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Affiliation(s)
- Anran Mao
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jiewei Chen
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xiaochen Bu
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Lulu Tian
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Weiwei Gao
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Eduardo Saiz
- Centre for Advanced Structural Ceramics, Department of Materials, Imperial College of London, London, SW7 2AZ, UK
| | - Hao Bai
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
- Institute of Zhejiang University-Quzhou, Quzhou, 324000, China
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