Abstract
The homopolymerizations of a series of 3-n-alkyl-1-vinylimidazolium iodides are described in which the length of the quaternizing alkyl group was varied from methyl to n-propyl to n-hexyl to n-heptyl to n-dodecyl to n-hexadecyl. The preparations of these cationic monomers have previously been reported through reaction of 1-vinylimidazole with the corresponding n-alkyl iodide. All polymerizations were performed in aqueous solution at the same molar concentration of monomer using the free radical initiator 4,4′-azobis-4-cyanopentanoic acid. It was found that the short side-chain polyions (methyl and n-propyl) were water soluble, whereas the more hydrophobic intermediate side-chain polyions (n-hexyl and n-heptyl) were water insoluble. The long side-chain polyions (n-dodecyl and n-hexadecyl), on the other hand, being highly hydrophobic, appeared to form polysoaps and remained in aqueous solution. The solution behavior of these polyions in water, in aqueous salt solution, and in chloroform is discussed as well as is the critical micelle concentration of a long side-chain polyion and its corresponding monomer.