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. [ILLEGIBLE] 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″,4,4″- p-terphenyltetracarboxylic dianhydride ( m = 1) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride ( m = 0), which had been previously prepared, and discussed on the basis of the number ( m) of phenylene units in the dianhydrides.