Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5180914 | Polymer | 2014 | 8 Pages |
The physical properties of the solutions of polyacrylonitrile (PAN) in N,N-dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO) were characterized in terms of solubility parameter. The physical properties were largely determined by individual solubility parameters, particularly the polar term, rather than overall solubility parameter. With increasing temperature, the intrinsic viscosity and hydrodynamic diameter of dilute solutions were decreased but the dynamic viscosity (ηâ²) of concentrated solutions was increased. Of the two solvents, these phenomena were more pronounced with DMF; DMF gave greater ηⲠand yield stress than DMSO. When the polymer solutions were dried at 25 °C DMSO generated a cocontinuous structure whereas DMF produced a dispersed morphology. In addition, DMF dissolved PAN faster than DMSO, and the dissolution process followed a mechanism analogous to SN2 reaction.
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