| 초록 |
The effects of chemical affinity of polar solvents on the physical properties of polyacrylonitrile (PAN) solutions were rheologically investigated. N,N-dimethylformamide (DMF) and dimethylsulfoxide (DMSO), having different polar characteristics, were selected to compare the physical properties of PAN solutions. Dynamic light scattering demonstrated that the coil dimension of individual chains in the solvents was diminished with increasing temperature. However, PAN/DMSO had greater intrinsic viscosity than PAN/DMF. In the high concentration regime, DMF gave greater dynamic viscosity and storage modulus of PAN than DMSO. During temperature- and time-induced gelation tests, gelation was further accelerated by increasing temperature. Especially, more rapid and sharper increase of viscosity was observed in DMF than in DMSO. Transmission electron microscopy revealed that the resultant phase morphology after evaporation of solvent was greatly dependent on the solvent and temperature. |
