Abstract：In this paper, 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 3,3',4,4'- biphenyltetracarboxylic dianhydride (BPDA), p-phenylenediamine (PDA) and 4,4'-oxydianiline (ODA) was used as raw material to prepare quaternary copolyamide acid. The rheological properties of the solution were studied. The shear viscosity of the solution and its influencing factors were discussed. The relationship between storage modulus (G') and loss modulus (G'') and mechanical loss (tanδ), angular frequency (ω) and temperature was studied under alternating strain. The results showed that polyamic acid solution was a pseudoplastic fluid and exhibits thixotropic behavior. The viscosity of the solution decreased with the increase of temperature, and the activation energy of viscous flow decreased with the increase of shear rate. The viscosity increased with the increase of solid content. The storage modulus and loss modulus increased with the increase of frequency and decrease with the increase of temperature. The mechanical loss tanδ decreased with the increase of frequency and increased with the increase of temperature.
