Structure investigation of narrow banded spherulites in polyhydroxyalkanoates by microbeam X-ray diffraction with synchrotron radiation
Structure investigation of narrow banded spherulites in polyhydroxyalkanoates by microbeam X-ray diffraction with synchrotron radiation
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DOI：
10.1016/j.polymer.2005.03.064
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发表时间：
2005-07
期刊：
影响因子：
4.6
通讯作者：
Toshihisa Tanaka;M. Fujita;A. Takeuchi;Yoshio Suzuki;K. Uesugi;Y. Doi;T. Iwata
中科院分区：
文献类型：
--
作者：
Toshihisa Tanaka;M. Fujita;A. Takeuchi;Yoshio Suzuki;K. Uesugi;Y. Doi;T. Iwata
采用同步辐射（SPring-8）菲涅尔波带板技术，通过微束X射线衍射研究了具有不同第二单体单元4-羟基丁酸酯、3-羟基己酸酯或6-羟基己酸酯的聚[(R)-3-羟基丁酸酯]（P(3HB)）及其共聚物的球晶的窄带结构。使用 0.5μm 光束直径的精细微焦点光束，以 2 或 4μm 步长进行球晶的径向扫描。 P(3HB)均聚物球晶的X射线衍射图显示晶体取向沿径向（a轴）变化，而b轴和c轴绕a轴旋转。 P(3HB) 共聚物球晶的微束 X 射线图中的强度随着沿径向方向的距离而周期性变化。 X 射线衍射测量的周期性与偏光光学显微镜观察到的窄带间距（15-25μm）相匹配。
Narrow banded structures of spherulites of poly[(R)-3-hydroxybutyrate] (P(3HB)) and its copolymers, with different second monomer unit of 4-hydroxybutyrate, 3-hydroxyhexanoate or 6-hydroxyhexanoate, were investigated by microbeam X-ray diffraction with Fresnel Zone Plate technique in synchrotron radiation (SPring-8). Radial scanning of spherulites were performed in 2 or 4μm steps with 0.5μm beam diameter of fine microfocus beam. The X-ray diffraction patterns for P(3HB) homopolymer spherulites showed the change of crystal orientation along the radial direction (a-axis), while the b- and c-axes rotated around a-axis. The intensities in microbeam X-ray diagrams of spherulites for P(3HB) copolymers changed periodically as function of the distance along the radial direction. The periodicity measured by X-ray diffraction was matched with narrow band spacing (15–25μm) observed by polarized optical microscopy.