A study of crystalline transitions in a thermoplastic polyimide

Abstract

A new polyimide derived from 4,4′‐isophthaloyldiphthalic anhydride (IDPA) and 1,3‐bis(4‐aminophenoxy‐4′‐benzoyl)benzene (1,3‐BABB) having semicrystalline behavior was prepared at NASA Langley Research Center in 1987. The crystalline transitions of this thermoplastic polyimide have been studied. The differential scanning calorimetry (DSC) pattern of partially imidized film exhibited two distinct crystalline melt endotherms. For this study each crystalline phase was isolated and enhanced by controlled thermal treatment. A film containing approximately 50% of both phases and an amorphous film were also prepared. Evaluations of these films were performed by DSC, wide‐angle x‐ray scattering (WAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Three distinct crystalline morphologies; ellipsoid, cubic, and needlelike embedded in an amorphous matrix were observed as a function of various cure conditions by SEM.

Synthesis, Characterization and Film Preparation of New Co-Polyimide Based on New 3,5-Diamino- N -(Pyridin-4-Ylmethyl)benzamide, Oda and 6fda

“…In Figure 10, it is seen that all samples form uniform films, that are typical of the manufacturing process used and the usual behaviour for these type of polymers. [39][40][41] Furthermore, it is possible to see small cavities on the surface of the films due to the formation of solvent droplets during the evaporation process. 42 The observed behaviour by FE-SEM is confirmed by the profiles obtained from AFM analysis (Figure 11) where the resulting images for the topography of PO6-5/5 is shown as an example.…”