In-situ WAXS study of the crystal structure of R-BAPB oligoimide during heating

Abstract

In the process of this work, an oligoimide FT-BAPB-R-BAPB-FT was synthesized, the particles of which consist of numerous lamellas having a semi-crystalline structure. On the DSC thermogram of oligoimide powder, two endo peaks were observed at 281.1°C and 306.4°C. A unique WAXS experiment was performed in-situ by heating the reactor oligoimid powder in a heat chamber. There was no significant difference in the X-ray profiles when the sample was heated. It should be noted that the transformation of the crystalline cell does not occur until the sample melts. It was revealed that the degree of crystallinity decreases during heating. We believe that the low-temperature endopeak is associated with the melting of small crystallites and amorphization of the sample. However, a significant increase in crystal size was found to be a result of recrystallization. Thus, the high-temperature endopic corresponds to the melting of larger crystallites.