Spectroscopic and thermal analyses of alpha ' and alpha crystalline forms of poly(L-lactic acid)
文献类型：期刊论文
| 作者 | Kalish, Jeffrey P.1; Aou, Kaoru1; Yang, Xiaozhen1,2; Hsu, Shaw Ling1 |
| 刊名 | POLYMER
 |
| 出版日期 | 2011-02-03 |
| 卷号 | 52期号:3页码:814-821 |
| 关键词 | Poly(L-lactic Acid) Polymorphic Phase Crystallization |
| ISSN号 | 0032-3861 |
| DOI | 10.1016/j.polymer.2010.12.042 |
| 英文摘要 | Poly(lactic acid) samples rich in alpha' or alpha crystals have been characterized using spectroscopic and thermal methods. Cryogenic infrared and Raman spectroscopy were used to probe the differences in chain conformation and packing. Compared to the alpha crystal, the alpha' crystal has weakened specific carbonyl and methyl interactions. Experimental spectroscopic analysis in conjunction with simulation studies have shown that the alpha' crystal has uniform conformational disorder in the C-alpha-C torsion angle. This disorder in chain conformation and packing leads to different crystalline forms with different stabilities. The difference in thermal stability was quantified by measuring enthalpic change at melting for both crystalline forms. Significantly different values for the two crystalline forms were obtained (Delta H degrees(m)(alpha') = 57 +/- 3 J g(-1) and Delta H degrees(m)(alpha) = 96 3J g(-1)). The transformation from the less stable a' to the more stable a phase has been characterized. This analysis provides an explanation to the double melting peaks usually found in PLLA samples. (C) 2010 Elsevier Ltd. All rights reserved. |
| 语种 | 英语 |
| WOS记录号 | WOS:000287013600029 |
| 出版者 | ELSEVIER SCI LTD |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/73073]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Hsu, Shaw Ling |
| 作者单位 | 1.Univ Massachusetts, Dept Polymer Sci & Engn, Mat Res Sci & Engn Ctr, Amherst, MA 01003 USA 2.Chinese Acad Sci, Inst Chem, Beijing 100080, Peoples R China |
| 推荐引用方式 GB/T 7714 | Kalish, Jeffrey P.,Aou, Kaoru,Yang, Xiaozhen,et al. Spectroscopic and thermal analyses of alpha ' and alpha crystalline forms of poly(L-lactic acid)[J]. POLYMER,2011,52(3):814-821. |
| APA | Kalish, Jeffrey P.,Aou, Kaoru,Yang, Xiaozhen,&Hsu, Shaw Ling.(2011).Spectroscopic and thermal analyses of alpha ' and alpha crystalline forms of poly(L-lactic acid).POLYMER,52(3),814-821. |
| MLA | Kalish, Jeffrey P.,et al."Spectroscopic and thermal analyses of alpha ' and alpha crystalline forms of poly(L-lactic acid)".POLYMER 52.3(2011):814-821. |
入库方式： OAI收割
来源：化学研究所
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