Crystallinity and Miscibility of Poly(vinyl isobutyl ether)/Poly(ε-L-lysine) Blends by Solid State 13C NMR Study
Crystallinity and Miscibility of Poly(vinyl isobutyl ether)/Poly(ε-L-lysine) Blends by Solid State 13C NMR Study
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通过固态 13C NMR 研究聚（乙烯基异丁基醚）/聚（ε-L-赖氨酸）共混物的结晶度和混溶性
DOI：
10.2324/ejsm.3.1
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Takuzo Kurotsu
中科院分区：
文献类型：
--
作者：
A. Asano;Y. Murata;Takuzo Kurotsu
通过 13C 交叉极化与魔角旋转 (CPMAS) NMR（核磁共振）和 DSC 测量研究了聚（乙烯基异丁基醚）（PVIBE）和聚（e-L-赖氨酸）（e-PL）半结晶聚合物共混物的结晶度和混溶性之间的关系。对从 PVIBE 和 e-PL 信号观察到的 1H 自旋晶格弛豫曲线（从高分辨率的 13C CPMAS NMR 光谱间接获得）进行分析表明，共混物中 e-PL 的域在 50-100 nm 范围内。考虑到 PVIBE 和 e-PL 之间 1H 自旋扩散速率的贡献，使用两自旋或三自旋模型来模拟 1H 弛豫曲线。此外，发现共混e-PL很大程度上影响PVIBE的结晶度，但除10/1组成外，共混PVIBE对e-PL的影响很小。观察到的 e-PL 熔点随着 PVIBE 含量的增加而向较低温度移动。这种转变可以通过吉布斯-汤姆逊效应来解释，即晶相厚度的减小导致熔点降低。
The relation between crystallinity and miscibility of semicrystalline polymer blends of poly(vinyl isobutyl ether) (PVIBE) and poly(e-L-lysine) (e-PL) is investigated by 13C cross-polarization with magic-angle-spinning (CPMAS) NMR (nuclear magnetic resonance) and DSC measurements. Analysis of the 1H spin-lattice relaxation curves observed from both PVIBE and e-PL signals, which are indirectly obtained from well-resolved 13C CPMAS NMR spectra, suggested that the domains of e-PL in the blends are in the range of 50–100 nm scale. Two-spin or three-spin models were used to simulate the 1H relaxation curves taking into account the contribution of a 1H spin-diffusion rate between PVIBE and e-PL. Furthermore, it was found that blending e-PL largely influences the crystallinity of PVIBE but that of e-PL is little affected by blending PVIBE except for 10/1 composition. The observed melting point of e-PL shifted towards lower temperature accompanied by PVIBE content. This shift was explained by the Gibbs-Thomson effect that the decrease of thickness of crystalline phase causes the depression of the melting point.