Influence of terminating triamine by phthalic anhydride on polyimides’ properties

In this study, hyperbranched polyimides were prepared from 2,6-bis(4-aminophenyl)-4-(4-(4-aminophenoxy)phenyl)pyridine (BAAP) and commercial dianhydrides by strictly controlling the reaction conditions. Polyimides with phthalimide pendants were also prepared to study the influence mechanisms of terminating BAAP by phthalic anhydride (PA) on polyimides’ properties. Fourier transform infrared and proton nuclear magnetic resonance spectroscopies were utilized to observe the chemical structures of the hyperbranched polyimides. The influence of terminating BAAP by PA on polyimides’ properties was studied by comparing the two series of polyimides. All the polyimide samples held completely amorphous structures and possessed excellent solubility and thermal stability. Terminating BAAP by PA decreased the d-spacing values of the obtained polyimides and slightly weakened their solubility and thermal stability.