Temperature-Variable FTIR and Solid-State C-13 NMR Investigations on Crystalline Structure and Molecular Dynamics of Polymorphic Poly(L-lactide) and Poly(L-lactide)/Poly(D-lactide) Stereocomplex
文献类型：期刊论文
| 作者 | Pan PJ(潘鹏举) ; Yang JJ(杨进军) ; Dan GR(单国荣) ; Bao YZ(包永忠) ; Weng ZX(翁志学) ; Cao AM(曹阿民) ; 矢泽宏次 ; 井上义夫 |
| 刊名 | Macromolecules
 |
| 出版日期 | 2012 |
| 卷号 | 45期号:1页码:189-197 |
| ISSN号 | 0024-9297 |
| 其他题名 | 变温傅里叶红外和固相13C核磁共振法研究多晶型L-聚乳酸和L-聚乳酸/D-聚乳酸立体复合物的晶体结构和分子动力学 |
| 通讯作者 | 潘鹏举 |
| 英文摘要 | Crystalline structure and molecular dynamics in alpha and alpha' crystals of poly(L-lactide) (PLLA) and PLLA/poly(Dlactide) (PDLA) stereocomplex (sc) crystals have been investigated by the temperature-variable FTIR and solid-state C-13 CP-MAS NMR spectroscopy. The crystal forms of polylactide (PLA) have different band frequencies, correlation field splittings in FTIR spectra and different line shapes, and resonance splittings in solid-state NMR spectra, which become more distinct with cooling to the cryogenic conditions. The well-resolved splittings in NMR resonances of alpha crystals, attributable to the crystallographically inequivalent sites within crystal unit cell, are considered to be due to the dipolar interactions related to the carbonyl, methyl, and methine groups. The splittings in FTIR bands and NMR resonances are absent in alpha' crystals, indicating the disordered conformation and loose molecular lateral packing within their crystal lattices. The significant FTIR frequency shifts of nu(C=O), nu(CH3), and nu(CH) modes during stereocomplex crystallization of PLLA/PDLA blend and the appearance of spectral splittings at cryogenic conditions suggest the coexistence of weak C-H center dot center dot O=C hydrogen bonds and dipolar interactions between PLLA and PDLA chains in the sc crystals of PLA Below the glass transition temperature (T-g), the spin lattice relaxation times of PLA with different crystalline structures increase in the order of amorphous approximate to alpha' < alpha < sc. |
| 学科主题 | 高分子化学 ; 分析化学 |
| 收录类别 | SCI |
| 原文出处 | http://dx.doi.org/10.1021/ma201906a |
| 语种 | 英语 |
| WOS记录号 | WOS:000298905000023 |
| 公开日期 | 2013-08-23 |
| 源URL | [http://202.127.28.38/handle/331003/28413]  |
| 专题 | 上海有机化学研究所_高分子材料研究室 |
| 推荐引用方式 GB/T 7714 | Pan PJ,Yang JJ,Dan GR,et al. Temperature-Variable FTIR and Solid-State C-13 NMR Investigations on Crystalline Structure and Molecular Dynamics of Polymorphic Poly(L-lactide) and Poly(L-lactide)/Poly(D-lactide) Stereocomplex[J]. Macromolecules,2012,45(1):189-197. |
| APA | 潘鹏举.,杨进军.,单国荣.,包永忠.,翁志学.,...&井上义夫.(2012).Temperature-Variable FTIR and Solid-State C-13 NMR Investigations on Crystalline Structure and Molecular Dynamics of Polymorphic Poly(L-lactide) and Poly(L-lactide)/Poly(D-lactide) Stereocomplex.Macromolecules,45(1),189-197. |
| MLA | 潘鹏举,et al."Temperature-Variable FTIR and Solid-State C-13 NMR Investigations on Crystalline Structure and Molecular Dynamics of Polymorphic Poly(L-lactide) and Poly(L-lactide)/Poly(D-lactide) Stereocomplex".Macromolecules 45.1(2012):189-197. |
入库方式： OAI收割
来源：上海有机化学研究所
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