Controlled and stereospecific polymerization of rac-lactide with a single-site ethyl aluminum and alcohol initiating system
文献类型:期刊论文
作者 | Tang, ZH; Yang, YK; Pang, X; Hu, JL; Chen, XS; Hu, NH; Jing, XB |
刊名 | JOURNAL OF APPLIED POLYMER SCIENCE
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出版日期 | 2005-10-05 |
卷号 | 98期号:1页码:102-108 |
关键词 | Ring-opening Polymerization Block Copolymers Stereospecific Polymers |
ISSN号 | 0021-8995 |
DOI | 10.1002/app.22049 |
英文摘要 | A single-site ethyl aluminum complex, [2,2-diethyl-1,3-propylenebis(3,5-di-tert-butyl-salicylideneimi- nato)] ethyl aluminum (2), with a geminal diethyl substitutent on the diamino bridge was synthesized by the reaction of AlEt3 with 1 equiv of N,N'-(2,2-diethyl-1,3-propylene)bis(3,5-di-tert-butylsalicylideneimine). X-ray diffraction showed that complex 2 contained a five-coordinate aluminum atom with a distorted trigonal bipyramidal geometry in the solid state. H-1-NMR and C-13-NMR spectra indicated that the two conformational enantiomers of 2 tautomerized quickly on the NMR timescale in solution. In the presence of isopropyl alcohol, the ring-opening polymerization (ROP) of rac-lactide with complex 2 produced a crystalline stereoblock polylactide (PLA). The stereoblocks contained an average of 12 units (L = 12) of enantiomerically pure lactic acid. There was a linear relationship between the monomer conversion and number-average molecular weights of the polymer. An induction period was observed for the polymerization. The induction period increased with decreasing concentration of catalyst 2 and isopropyl alcohol. In the presence of poly(ethylene glycol) (PEG), a PLA/PEG/PLA stereocomplex was prepared directly by the ROP of rac-lactide with complex 2, which was confirmed by NMR, gel permeation chromatography, wide-angle X-ray diffraction, and differential scanning calorimetry. (c) 2005 Wiley Periodicals, Inc. |
语种 | 英语 |
WOS记录号 | WOS:000231367700015 |
出版者 | JOHN WILEY & SONS INC |
源URL | [http://ir.iccas.ac.cn/handle/121111/57281] ![]() |
专题 | 中国科学院化学研究所 |
通讯作者 | Chen, XS |
作者单位 | Chinese Acad Sci, Changchun Inst Appl Chem, Grad Sch, State Key Lab Polymer Phys & Chem, Changchun 130022, Peoples R China |
推荐引用方式 GB/T 7714 | Tang, ZH,Yang, YK,Pang, X,et al. Controlled and stereospecific polymerization of rac-lactide with a single-site ethyl aluminum and alcohol initiating system[J]. JOURNAL OF APPLIED POLYMER SCIENCE,2005,98(1):102-108. |
APA | Tang, ZH.,Yang, YK.,Pang, X.,Hu, JL.,Chen, XS.,...&Jing, XB.(2005).Controlled and stereospecific polymerization of rac-lactide with a single-site ethyl aluminum and alcohol initiating system.JOURNAL OF APPLIED POLYMER SCIENCE,98(1),102-108. |
MLA | Tang, ZH,et al."Controlled and stereospecific polymerization of rac-lactide with a single-site ethyl aluminum and alcohol initiating system".JOURNAL OF APPLIED POLYMER SCIENCE 98.1(2005):102-108. |
入库方式: OAI收割
来源:化学研究所
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