Study On The Relationship Between Structure And Viscoelasticity Of PAN Spinning Solution

The structure of PAN and the rheological behavior of PAN spinning solution were studied in this paper. Firstly, the methods of 13C-NMR and IR spectrum were used to evaluate the triad tacticity of PAN. The results showed that the result calculated by the method of ¹³C-NMR were near to the theoretic value. Secondly, the results of DSC showed that T_g of PAN had no relationship with molecule weight of PAN and may have relationship with molecule construction. Thirdly, the rheological properties and viscoelasticity of PAN spinning solutions were studied by means of revolving rheometer under the scan modes of steady shear rate (frequency) and dynamic frequency. The effects of shear rate, temperature and molecule weight on its rheological properties were studied. It was found that PAN solution is a kind of pseudoplastic fluid. Moreover, with the increase of shear rate (frequency), the apparent shear viscosity, activation energy of viscous flow and Non-Newtonian viscous index decreased while the first normal-stress difference, the loss modulus and storage modulus increased. In addition, with the increase of temperature, the apparent shear viscosity, zero shear viscosity, structural viscosity index and first normal-stress difference, the loss modulus...