The effect of the 3-hydroxyhexanoate content on isothermal crystallization behavior from the melt was investigated for microbial poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHs) having the 3-hydroxyhexanoate (3HH) contents of 0, 3.2, 5.8, and 10.6 mol % by time-resolved wide-angle X-ray diffraction and small-angle X-ray scattering simultaneous measurements using synchrotron radiation and rapid differential scanning calorimetry. The isothermal crystallization temperatures after completion of the rapid temperature jump from the melt were ca. 61, 71, 82, and 91 °C. It was found that the nucleation rate and crystallization rate decreased with increasing the 3HH contents in the PHBHs. The ratio of orthorhombic lattice constants a to b as well as the lamellar thickness during crystallization might be changed corresponding to formation of the unstable “intermediate structures” and transformation from them to thermostable regular crystal structures. The 3HH units prevented the 3HB units from formation of not only the “intermediate structures” having mesomorphic layers but also the well-ordered crystal structures of lamellae.

中文翻译：

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3-羟基己酸酯含量对微生物聚（3-羟基丁酸酯-共-3-羟基己酸酯）熔融等温结晶行为的影响

上从熔融等温结晶行为的3-羟基己酸酯含量的影响进行了研究的微生物聚（3-羟基丁酸酯共具有3羟基己酸酯（3HH）的0内容，3.2，5.8 -3-羟基己酸酯）（PHBHs），通过使用同步辐射和快速差示扫描量热法的时间分辨广角 X 射线衍射和小角 X 射线散射同时测量，10.6 mol%。从熔体快速温度跃升完成后的等温结晶温度约为 61、71、82 和 91 °C。发现随着PHBHs中3HH含量的增加，成核速率和结晶速率降低。正交晶格常数a与b的比值以及结晶过程中的层状厚度可能会随着不稳定的“中间结构”的形成以及从它们转变为热稳定的规则晶体结构而发生变化。3HH 单元不仅阻止了 3HB 单元形成具有介晶层的“中间结构”，而且阻止了片晶有序晶体结构的形成。