Volume 39, Issue 7 pp. 1927-1935
Concise Report

From Polymerization Inhibition to Controlled Ring-Opening Metathesis Polymerization of Macromonomers with Tertiary Amine Groups: The Effect of Spacer Chain

Tengda Zhao

Tengda Zhao

School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin, 300350 China

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Kongying Zhu

Kongying Zhu

Analysis and Measurement Center, Tianjin University, Tianjin, 300072 China

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Xiaoliang Yu

Xiaoliang Yu

School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin, 300350 China

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Xiaoyan Yuan

Xiaoyan Yuan

School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin, 300350 China

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Lixia Ren

Corresponding Author

Lixia Ren

School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin, 300350 China

E-mail: [email protected]Search for more papers by this author
First published: 26 March 2021
Citations: 3

Dedicated to the Special Issue of Polymer Synthesis.

Main observation and conclusion

Ring-opening metathesis polymerization (ROMP) is a powerful toolbox in preparation of bottlebrush polymers for its high activity. However, the ROMP of macromonomers with repeating tertiary amine groups, for example, poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA), is inhibited due to the coordination of nitrogen atom with ruthenium center ([Ru]) in the third generation Grubbs catalyst (G3). In this work, norbornenyl functionalized polystyrene-block-PDMAEMA (NB-PS-b-PDMAEMA) macromonomers with different length of polystyrene (PS) spacers are prepared. The PS spacers provide non-coordinating local environment to protect [Ru] in G3 from coordinating with tertiary amine groups. Kinetic studies show that the PS spacer with polymerization degree (DP) of 15 is enough to protect G3, and the polymerization is controlled. However, the PS spacer with DP of 5 is inhibited within 10 min. In situ proton nuclear magnetic resonance studies show that the [Ru] in G3 is active during the ROMP of NB-PS15-b-PDMAEMA39, which is inactive gradually for NB-PS5-b-PDMAEMA42. In comparison, the ROMP of NB-PDMAEMA macromonomer without spacer chain is inhibited and the G3 catalyst is inactive from the beginning. By introducing non-coordinating spacer chain with enough length, the ROMP of macromonomers with tertiary amine groups is controlled, which provides a new strategy for the preparation of bottlebrush polymers with functional amine groups.image

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