Aromatic Polyimides Containing p-Quarterphenyl and p-Sexiphenyl Units

We have prepared aromatic polyimides PI-Ar-m containing p-quarterphenyl (m = 2) and p-sexiphenyl (m = 4) units. These polyimides are characterized by having long phenylene units and the introduction of these has a strong influence on the properties of polyimides. In this paper, the properties of polyimides are compared with those of polyimides from 3,3-34,4-3-p-terphenyltetracarboxylic dianhydride (m = 1) and 3,3-24,4-2-biphenyltetracarboxylic dianhydride (m = 0), which had been previously prepared, and discussed on the basis of the number (m) of phenylene units in the dianhydrides.