Volume 43, Issue 9 pp. 983-994
Concise Report

Well-Controlled Block-Type Cyclic Olefin Copolymers with High Heat Resistance, Outstanding Strength and Low-Temperature Toughness

Dong Huang

Dong Huang

Tianjin Key Laboratory of Composite and Functional Materials, and School of Materials Science and Engineering, Tianjin University, Tianjin, 300072 China

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Jin Li

Jin Li

Petrochemical Research Institute, Petro China Company Limited, Beijing, 102206 China

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Xu Lu

Xu Lu

Petrochemical Research Institute, Petro China Company Limited, Beijing, 102206 China

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Kunyu Zhang

Kunyu Zhang

Petrochemical Research Institute, Petro China Company Limited, Beijing, 102206 China

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Fei Wang

Fei Wang

Tianjin Key Laboratory of Composite and Functional Materials, and School of Materials Science and Engineering, Tianjin University, Tianjin, 300072 China

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Di Wu

Di Wu

Tianjin Key Laboratory of Composite and Functional Materials, and School of Materials Science and Engineering, Tianjin University, Tianjin, 300072 China

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Yafei Wang

Yafei Wang

Tianjin Key Laboratory of Composite and Functional Materials, and School of Materials Science and Engineering, Tianjin University, Tianjin, 300072 China

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Li Pan

Corresponding Author

Li Pan

Tianjin Key Laboratory of Composite and Functional Materials, and School of Materials Science and Engineering, Tianjin University, Tianjin, 300072 China

E-mail: [email protected]Search for more papers by this author
Yang Li

Yang Li

Petrochemical Research Institute, Petro China Company Limited, Beijing, 102206 China

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Yuesheng Li

Yuesheng Li

Tianjin Key Laboratory of Composite and Functional Materials, and School of Materials Science and Engineering, Tianjin University, Tianjin, 300072 China

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First published: 28 January 2025
Citations: 2

Comprehensive Summary

As an important class of transparent polyolefins, cyclic olefin copolymers (COCs) exhibit a wide range of properties, from soft (low cyclic unit content in a random copolymer) to hard (high cyclic unit content in a random copolymer) thermoplastics. A higher cyclic unit content in a random copolymer results in increased rigidity and heat resistance, but at the expense of material toughness, especially under low temperature. To achieve a trade-off, block-type COCs composed of well-defined hard-soft and hard-soft-hard segments with high molecular weights (Mn > 200 kDa) and relatively narrow molecular weight distributions (Mw/Mn < 1.42) were prepared via quasi-living copolymerization. Compared to random copolymers, di-block COCs retained satisfactory heat resistance and optical transparency and exhibited superior tensile properties (tensile strength: 56.2 MPa, elongation at break: 254.4%), while tri-block COCs with the same hard-soft segments and an additional hard segment exhibited even better tensile properties, achieving a tensile strength of 67.3 MPa, elongation at break of 286.9%, all while maintaining high optical transmittance (> 90%). Even at temperatures below 0 °C, the tri-block copolymers EN52-b-EN19-b-EN46 demonstrated a satisfactory tensile strength (> 64.0 MPa) and elongation at break (> 65.6%), highlighting the advantages of the alternating hard-soft segment structural design in COCs.

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