Ligand-Free Magnesium Catalyst System: Immortal Polymerization of L-Lactide with High Catalyst Efficiency and Structure of Active Intermediates
文献类型：期刊论文
| 作者 | Wang, Yang1,2; Zhao, Wei1,2; Liu, Xinli1; Cui, Dongmei1; Chen, Eugene Y. -X.3 |
| 刊名 | MACROMOLECULES
 |
| 出版日期 | 2012-09-11 |
| 卷号 | 45期号:17页码:6957-6965 |
| ISSN号 | 0024-9297 |
| DOI | 10.1021/ma3007625 |
| 英文摘要 | A simple, inexpensive, and convenient catalyst system consisting of supporting ligand-free (MgBu2)-Bu-n in combination with an alcohol, isopropanol ((PrOH)-Pr-i), benzyl methanol (PhCH2OH), diphenylmethanol (Ph2CHOH), or triphenylmethanol (Ph3COH), generates a convenient catalyst system to promote the polymerization of L-LA. In particular, the binary system (MgBu2)-Bu-n/Ph2CHOH demonstrates an unprecedentedly high activity in the presence of a large excess amount of Ph2CHOH with the [OH](0)/[Mg](0) ratio varying from 2 to 500, producing up to 500 polylactide (PLA) chains per Mg center and thus showing a typical nature of immortal polymerization. The molecular weights of the obtained PLAs with a broad range of monomer-to-metal ratios ([L-LA](0)/[Mg](0) = 200-5000) are rather accurately controlled by the Ph2CHOH loading, relative to [Mg](0), while the molecular weight distributions remain nearly constant with polydispersity index (PDI) = 1.08-1.18. Moreover, the active polymerization intermediate has been isolated from the stoichiometric reaction between (MgBu2)-Bu-n and Ph2CHOH and structurally characterized as a tetranuclear complex, Mg-4(Ph2CHO)(8)(THF)(2) (1). Complex 1 remains the tetranuclear structure in solution or in the presence of excess Ph2CHOH as determined by 2D DOSY. On the basis of structural information about the active intermediates and polymerization kinetics, a coordination insertion polymerization mechanism is proposed. |
| 语种 | 英语 |
| WOS记录号 | WOS:000309014000023 |
| 出版者 | AMER CHEMICAL SOC |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/49819]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Cui, Dongmei |
| 作者单位 | 1.Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Polymer Phys & Chem, Changchun 130022, Peoples R China 2.Chinese Acad Sci, Grad Sch, Beijing 100039, Peoples R China 3.Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA |
| 推荐引用方式 GB/T 7714 | Wang, Yang,Zhao, Wei,Liu, Xinli,et al. Ligand-Free Magnesium Catalyst System: Immortal Polymerization of L-Lactide with High Catalyst Efficiency and Structure of Active Intermediates[J]. MACROMOLECULES,2012,45(17):6957-6965. |
| APA | Wang, Yang,Zhao, Wei,Liu, Xinli,Cui, Dongmei,&Chen, Eugene Y. -X..(2012).Ligand-Free Magnesium Catalyst System: Immortal Polymerization of L-Lactide with High Catalyst Efficiency and Structure of Active Intermediates.MACROMOLECULES,45(17),6957-6965. |
| MLA | Wang, Yang,et al."Ligand-Free Magnesium Catalyst System: Immortal Polymerization of L-Lactide with High Catalyst Efficiency and Structure of Active Intermediates".MACROMOLECULES 45.17(2012):6957-6965. |
入库方式： OAI收割
来源：化学研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。