The crystalline morphology of a thermotropic aromatic polyester crystallized from st nematic melt was investigated by means of polarized optical microscopy (POM) and scanning electron microscopy (SEM). Due to POM measurements it was found that spherulites of two different types are formed within the two different temperature regions. When T-c was exceeding 170 degrees C, spherulites of type-1 showing a negative birefringence grew with a radial fibrillar morphology and exhibited a clear Maltese-cross pattern. The radius growth rate of type-2 spherulites was about 2.2 mu m/min at 185 degrees C. When T-c was smaller than 160 degrees C, spherulites of type-2 were formed and exhibited a radially outward growing structure hut no evident Maltese-cross pattern. These spherulites could be seen by the naked eyes due to their size reaching several millimeters. SEM observations revealed that the spherulites of type-1 exhibited a ripple-like homocentric morphology with periodical compact fibrils having a diameter of about 150 nm perpendicular to the radial direction, fn contrast, the spherulites of type-2 exhibited, as apparent from performed SEM images, radially growing crystallites of about 500 nm in size with no periodicity in the radial direction. [References: 11]
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