Polyimides Containing a Quinazolinone Moiety

Abstract

A novel heterocyclic diamine monomer, 2-(4-aminophenyl)-6-amino-4(3H)-quinazolinone was synthesized from readily available compounds in three steps in high yield. A series of novel polyimides containing the quinazolinone moiety were synthesized either by a one-step solution polymerization reaction or by a two-step procedure that included a ring-opening polyadddition to give poly(amic acid)s, followed by cyclodehydration to polyimides. In the one-step method in m-cresol or p-chlorophenol with isoquinoline catalyst, polyimides with inherent viscosities of 0.44−0.63 dL/g were obtained. Polyimides 4f and 4g from dianhydrides which have a flexible linkage, hexafluoroisopropylidene dianhydride (2f) and BPA dianhydride (2g), were soluble in hot m-cresol and could be cast into tough films from m-cresol solution. In the two-step method, poly(amic acid)s with inherent viscosity between 0.63 and 1.40 dL/g were obtained in DMAc at room temperature. The poly(amic acid)s were converted to the corresponding polyimide fi...