| 采用固体NMR研究MPEG-PLA双嵌段共聚物的固态相区结构 |
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| 引用本文： | 伍国琳,孙平川,张国林,马建标.采用固体NMR研究MPEG-PLA双嵌段共聚物的固态相区结构[J].波谱学杂志,2003,20(1):1-7. |
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| 作者姓名： | 伍国琳 孙平川 张国林 马建标 |
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| 作者单位： | 南开大学高分子化学研究所，吸附分离功能高分子材料国家重点实验室，天津 300071 |
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| 基金项目： | 国家自然科学基金 (2 0 1 740 1 8)，高等学校重点实验室访问学者基金资助项目 |
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| 摘 要： | 采用固体核磁共振方法，研究了AB型聚（L-丙氨酸）聚乙二醇嵌段共聚物(MPEG-b-PLA）的固态微相结构. 13C核的交叉极化与直接极化实验表明，MPEG中存在晶态和非晶态两种相区结构，PLA则含有大量的α螺旋与少量的β折叠二级结构. 由交叉极化过程下的13C自旋-晶格弛豫时间(T1)测定结果进一步表明，MPEG链段由于嵌段结构使结晶过程受抑制，结晶度明显下降. PLA链段以结晶态形式存在，并由于大量α螺旋和β折叠有序结构的存在, 链段非常刚性，运动严重受限，而β位甲基因为可以自由旋转，所以运动能力较α位次甲基和羰基强.
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| 关 键 词： | 核磁共振 固体NMR 嵌段共聚物 相区结构 |
| 文章编号： | 1000-4556(2003)01-0001-07 |
| 收稿时间： | 2002-10-18 |
| 修稿时间： | 2002年10月18日 |
THE STRUCTURE OF A MPEG-b-PLA DIBLOCK COPOLYMER IN ITS SOLID PHASE STUDIED BY SOLID-STATE NMR |
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| WU Guo lin,SUN Ping chuan,ZHANG Guo lin,MA Jian biao\.THE STRUCTURE OF A MPEG-b-PLA DIBLOCK COPOLYMER IN ITS SOLID PHASE STUDIED BY SOLID-STATE NMR[J].Chinese Journal of Magnetic Resonance,2003,20(1):1-7. |
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| Authors: | WU Guo lin SUN Ping chuan ZHANG Guo lin MA Jian biao\ |
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| Institution: | State Key Laboratory of Functional Polymer Materials for Adsorption and Separation, Institute of Polymer Chemistry, Nankai University, Tianjin 300071, China |
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| Abstract: | In this work, the structure of a poly(ethylene glycol) methyl ether-b- poly(L-alanine) copolymer (MPEG-b-PLA) in its solid- state was studied by 13C CP/MAS, DP/MAS and spin lattice relaxation time T1 NMR experiments. The results revealed that the PEG blocks are crystallizable in the solid state of the diblock polymer, but the degree of crystallinity is considerably lower in the diblock polymer state than that in pure PEG. It was found that the PLA blocks is rigid not only because of the formation of a large number of α-helices and a small number of β-sheets as secondary structures, but also owing to PLA crystallinity in the solid state. The results also implied that Cβ is more mobile than Cα at room temperature, and the β-methyl group rotates freely around its axis. |
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| Keywords: | NMR solid state NMR MPEGb PLA block copolymer |
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