Polymerization of rac-lactide using schiff base aluminum catalysts: Structure, activity, and stereoselectivity
文献类型：期刊论文
| 作者 | Du, Hongzhi; Pang, Xuan; Yu, Haiyang; Zhuang, Xiuli; Chen, Xuesi; Cui, Dongmei; Wang, Xianhong; Jing, Xiabin |
| 刊名 | MACROMOLECULES
 |
| 出版日期 | 2007-03-20 |
| 卷号 | 40期号:6页码:1904-1913 |
| ISSN号 | 0024-9297 |
| DOI | 10.1021/ma062194u |
| 英文摘要 | A series of aluminum ethyls and isopropoxides based upon N,N,O,O-tetradentate Schiff base ligand framework have been prepared. X-ray diffraction analysis and H-1 NMR confirmed that these Schiff base aluminum ethyls and isopropoxides were all monomeric species with a five-coordinated central aluminum in their solid structures. Compared to the aluminum ethyls which all retain their monomeric structure in the solution, the dinucleating phenomenons of aluminum isopropoxides with less steric hindered substituents in the solution have also been observed. The activities and stereoselectivities of these complexes toward the ring-opening polymerization of rac-lactide have been investigated. Polymerization experiments indicated that (SB-2d)(AlOPr)-Pr-i [(SB-2d) = 2,2-dimethyl-1,3-propylenebis(3,5-di-tert-butylsalicylideneiminato)] exhibited the highest stereoselectivity and (SB-3b)(AlOPr)-Pr-i [(SB-3b) = 2,2-dimethyl-1,3-propylenebis(3,5-dichlorinesalicylideneiminato)] possessed the highest activity among these aluminum isopropoxides. The substituents and the mode of the bridging part between the two nitrogen atoms both exerted significant influences upon the progress of the polymerizations, influencing either the tacticity of isolated polymers or the rate of polymerization. The polymerization kinetics using (SB-3b)(AlOPr)-Pr-i as a catalyst were studied in details, and the experimental results revealed that the rate of polymerization was first-order in [LA] and 1.81th-order with respect to (SB-3b)(AlOPr)-Pr-i, which indicated that the propagating species was not uniform in the system without the protection of steric hindered substituents. Furthermore, the polymerization by initiating with (SB-3b)(AlOPr)-Pr-i could be progressed at low temperatures (0 degrees C) without the change of stereoselectivity. |
| 语种 | 英语 |
| WOS记录号 | WOS:000244855500024 |
| 出版者 | AMER CHEMICAL SOC |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/62511]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Chen, Xuesi |
| 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 |
| 推荐引用方式 GB/T 7714 | Du, Hongzhi,Pang, Xuan,Yu, Haiyang,et al. Polymerization of rac-lactide using schiff base aluminum catalysts: Structure, activity, and stereoselectivity[J]. MACROMOLECULES,2007,40(6):1904-1913. |
| APA | Du, Hongzhi.,Pang, Xuan.,Yu, Haiyang.,Zhuang, Xiuli.,Chen, Xuesi.,...&Jing, Xiabin.(2007).Polymerization of rac-lactide using schiff base aluminum catalysts: Structure, activity, and stereoselectivity.MACROMOLECULES,40(6),1904-1913. |
| MLA | Du, Hongzhi,et al."Polymerization of rac-lactide using schiff base aluminum catalysts: Structure, activity, and stereoselectivity".MACROMOLECULES 40.6(2007):1904-1913. |
入库方式： OAI收割
来源：化学研究所
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