Abstract
Since dimethylformamide has shown to be a good electrolyte in the presence of a large amount of vinyl acetate, the polarographic behaviors of some impurities in vinyl acetate such as divinylacetylene, crotonaldehyde, acetaldehyde and of a few aliphatic aldehydes related with them were studied in dimethylformamide and in demethylformamide-vinyl acetate-water systems, with tetraalkylammonium salt as a supporting salt.
In the dimethylformamide system, named compounds showed characterise half wave potentials of the system. Divinylacetylene gave a two-step wave at -1.74 V and -2.22 V. As for unsaturated aldehyde, crotonaldehyde gave a one-step wave at -1.48V, and acrolein at -1.29V. Saturated aldehydes, such as acetaldehyde, n-butylaldehyde and propionaldehyde, gave a one-step wave at -2.25V. Also, in a system where D. M. F contained 75% vinyl acetate, the first wave of divinylacetylene and a reducing wave of crotonaldehyde were very clear. Although the reducing wave of saturated aldehyde is covered by the presence of vinyl acetate, a reducing wave apeared at around -1.9V with great diffusion current in the D. M. F.-water-vinyl acetate system.
