Abstract The morphology of partially crystalline/ordered poly(butylene naphthalate) (PBN) forming on cooling the melt has been analyzed by polarized-light optical microscopy (POM) and microfocus-beam X-ray diffraction (XRD). Crystallization at rather low supercooling of the melt, at temperatures higher than about 200 °C, leads to slow and irregular spherulitic growth of β′-crystals, with spherulites not showing a distinct Maltese cross in POM. At temperatures between approximately 200 and 160 °C, the melt partially converts directly to α-crystals, and the obtained spherulitic superstructure reveals an increasing nuclei density with decreasing crystallization temperature. At even lower temperature, a liquid crystalline (LC) phase develops. This mesophase may subsequently convert to α-crystals according to Ostwald’s rule of stages. The transition of the LC-phase into α-crystals is suppressed at temperatures lower than about 120 °C or on cooling faster than about 200–500 K/s. X-ray analysis of PBN liquid crystals formed at well-defined cooling conditions in a fast scanning chip calorimeter revealed smectic periodicity while there is simultaneously observed a distinct Schlieren texture in POM.

中文翻译：

---

快速冷却的聚萘二甲酸丁二醇酯中的近晶液晶纹影结构

摘要 通过偏光光学显微镜 (POM) 和微聚焦束 X 射线衍射 (XRD) 分析了冷却熔体时形成的部分结晶/有序聚萘二甲酸丁二醇酯 (PBN) 的形貌。在熔体相当低的过冷度下结晶，温度高于约 200 °C，导致 β'-晶体缓慢且不规则的球晶生长，球晶在 POM 中没有显示出明显的马耳他十字。在大约 200 到 160 °C 之间的温度下，熔体部分直接转化为 α 晶体，并且获得的球晶超结构显示出随着结晶温度降低而增加的核密度。在更低的温度下，会形成液晶 (LC) 相。根据奥斯特瓦尔德阶段法则，该中间相随后可能会转化为 α 晶体。当温度低于约 120 °C 或冷却速度超过约 200–500 K/s 时，LC 相向 α 晶体的转变受到抑制。在快速扫描芯片量热仪中在明确定义的冷却条件下形成的 PBN 液晶的 X 射线分析显示近晶周期性，同时在 POM 中观察到明显的纹影结构。