| 초록 |
The rheological properties of highly concentrated poly(acrylonitrile) (PAN) solutions in N,N-dimethyl formamide (DMF) were investigated in terms of temperature and concentration. Highly concentrated PAN solutions in DMF were manufactured by new melter from 20wt% to 40wt%. The rheological properties of PAN/DMF solutions were measured by advanced rheometric expansion system (ARES). Over the temperature range of 60 and 120℃, the rheological properties of PAN/DMF solutions revealed a very unusual behavior. As temperature increased, the zero shear viscosity of PAN/DMF solutions was increased and the dynamic viscosity was merged at high frequency. also yield stress was increased with increasing temperature. On the other hands, as concentration increased, the dynamic viscosity was increased over all frequency region. |
