One-step synthesis of aromatic polyimides based on 4,4'-diaminotriphenylmethane

The feasibility of using a one-step high-temperature polycondensation for the synthesis of aromatic polyimides, based on 4,4'-diaminotriphenylmethane (DA-TPM), was studied. It was found that the reaction of DA-TPM with various aromatic dianhydrides in nitrobenzene at 180-200 degrees C resulted in the formation of the high molecular weight soluble polyimides, PI-TPM. The reaction solutions cooled to ambient temperature were used for casting films. These PI-TPM films significantly exceeded their prototypes obtained by the thermal imidization of poly(amic acids) in terms of solubility and tensile properties. All studied polyimides demonstrated well-distinguished glass transition at 260-320 degrees C. (C) 1996 John Wiley & Sons, Inc.