Physicochemical and thermal effects of pendant groups, spatial linkages and bridging groups on the formation and processing of polyimides

Abstract

Aromatic polyimides are known for their remarkable thermal and chemical properties which are greatly influenced by their precursors. In this study, we report synthesis and characterization of four different aromatic polyimides. The four different dianhydrides (ODPA, BTDA, BPDA, and PMDA) were reacted with a diamine (BisAPAF) via azeotropic imidization under same conditions. FTIR analysis confirmed the formation of aromatic polyimides and all but one polyimide (HPI-BPDA) were found to be completely soluble in common solvents. The obtained molecular weights were between 16,000 and 32,000 g/mol, glass transition temperatures were between 250 °C and 275 °C, degradation temperatures were above 550 °C, and the d-spacing values were around 5 Å. These properties are promising and can be beneficial for various applications such as thin films and membranes.

Keywords:

• Aromatic polyimides
• azeotropic imidization
• glass transition temperature
• molecular weight
• solubility

Acknowledgments

We would like to thank Dr. Guodung Du and his students in the Chemistry department for their help with the GPC analysis.

Disclosure of potential conflicts of interest

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the NSF ND EPSCoR Grant Project number UND0020709 through the NSF grand (#IIA135466).