Synthesis and Solution Properties of Polyt[N, N′(p-phenylene)-3,.3′,4,4′-biphenyltetracarboxylic acid diamide]

The polyimide poly[N, N′-(p-phenylene)-3,3′,4,4′-biphenyltetracarboxylic acid diimide] (BPDA-PDA) is used as a dielectric material in the electronics industry. Although the imidized polymer is insoluble in any organic solvent, the precursor polyamic acid is soluble in amide-type solvents or dimethyl sulfoxide (DMSO). A series of 10 polymers from the polycondensation of 3,3′,4,4′-biphenyltetracarboxylic acid dianhydride (BPDA) and p-phenylenediamine (PDA) with 4800 < Mw < 75 000 have been synthesized by controlling the stoichiometry. The solution properties were investigated in NMP (AT-methylpyrrolidinone) and DMSO by using low-angle light scattering, viscometry, and size exclusion chromatography with a light scattering detector. Estimates of the molecular flexibility from the dilute solution properties are compared with those calculated based on a freely rotating model. © 1991, American Chemical Society. All rights reserved.