The effect of alkali salt on solvent–polyacrylonitrile interaction

In solvent spinning of polyacrylonitrile from DMF or DMSO, it is observed that complete removal of solvent is rather difficult. It is shown that addition of Lithium salt, e.g., lithium bromide to the solution before casting a film helps in removing the solvent easily. The probable mechanism of the action of lithium salt in solvent removal is investigated, and it has been shown that the formation of coordinate linkage with the ion stops solvent bonding.