A Pseudo-Block Copolymerization Access to Cyclic Alternating Copolymers through Segment-Selective Transesterification.

• Tác giả: Fengzhuang Liu, Hongxin Zhang, Junpeng Zhao, Hongxuan Zhu
• Ngôn ngữ: eng
• Ký hiệu phân loại: 133.531 Sun
• Thông tin xuất bản: United States : ACS macro letters , 2025
• Bộ sưu tập: NCBI
• ID: 177453

Tóm tắt

 Efficient synthesis of cyclic polymers remains a frontier challenge. We report here that macromolecular transesterification during a pseudoblock copolymerization process can be utilized for such a purpose. Organobase-catalyzed ring-opening alternating copolymerization of 3,4-dihydrocoumarin and epoxide is conducted with four-armed poly(ethylene oxide) (PEO) as a macroinitiator. Intramolecular transesterification (backbiting) occurs selectively on the newly formed polyester segments. The disconnected cyclic alternating copolymers can be easily isolated by precipitation owing to their substantial solubility difference from the PEO-containing acyclic parts. The obtained cyclic alternating copolymers exhibit low dispersity (<
 1.2) and a molar mass of around 3 kg mol