Microstructure Analysis of a CO2 Copolymer from Styrene Oxide at the Diad Level
发表时间：2019-03-09
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- 论文类型：
- 期刊论文
- 第一作者：
- Wu, Guang-Peng
- 通讯作者：
- Lu, XB (reprint author), Dalian Univ Technol, State Key Lab Fine Chem, Dalian 116024, Peoples R China.
- 合写作者：
- Zu, Yu-Ping,Xu, Peng-Xiang,Ren, Wei-Min,Lu, Xiao-Bing
- 发表时间：
- 2013-08-01
- 发表刊物：
- CHEMISTRY-AN ASIAN JOURNAL
- 收录刊物：
- SCIE、EI、PubMed、Scopus
- 文献类型：
- J
- 卷号：
- 8
- 期号：
- 8,SI
- 页面范围：
- 1854-1862
- ISSN号：
- 1861-4728
- 关键字：
- copolymerization; NMR spectroscopy; poylmers; stereochemistry; styrene oxide
- 摘要：
- A large amount of interesting information on the alternating copolymerization of CO2 with terminal epoxides has already been reported, such as the regiochemistry of epoxide ring-opening and the stereochemistry of the carbonate unit sequence in the polymer chain. Moreover, the microstructures of CO2 copolymers from propylene oxide and cyclohexene oxide have also been well-studied. However, the microstructure of the CO2 copolymer from styrene oxide (SO), an epoxide that contains an electron-withdrawing group, has not yet been investigated. Herein, we focus on the spectroscopic assignment of the CO2 copolymer from styrene oxide at the diad level by using three kinds of model dimer compounds, that is, T-T, H-T, and H-H. By comparing the signals in the carbonyl region, we concluded that the signals at =154.3, 153.8, and 153.3ppm in the 13CNMR spectrum of poly(styrene carbonate) were due to tail-to-tail, head-to-tail, and head-to-head carbonate linkages, respectively. Moreover, various isotactic and syndiotactic model compounds based on T-T, H-T, and H-H (dimers (R,R)-T-T, (S,S)-T-T, and (R,S)-T-T; (R,R)-H-T, (S,S)-H-T, and (R,S)-H-T; (R,R)-H-H, (S,S)-H-H, and (R,S)-H-H) were synthesized for the further spectroscopic assignment of stereospecific poly(styrene carbonate)s. We found that the carbonate carbon signals were sensitive towards the stereocenters on adjacent styrene oxide ring-opening units. These discoveries were found to be well-matched to the microstructures of the stereoregular poly(styrene carbonate)s that were prepared by using a multichiral CoIII-based catalyst system.
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- 否
