CELLULOSE DIALDEHYDE - COMPARISON OF THE METHODS OF DETERMINATION

The three methods currently used for the determination of aldehyde gro ups in dialdehyde cellulose (reaction with NH2OH - HCl, oxidation by a lkaline iodine and reduction with NaBH4) were compared. The phenomenon of ''ageing'' of cellulose dialdehyde was observed ; depending upon t he lenght of storage time decrease of effective present, determinable aldehyde groups were found (using the NH2OH . HCl method till 11% duri ng two months). Decrease of determinable aldehyde groups in cellulose dialdehyde is reversible. Practically, the original values could be re ached after heating up the aqueous suspension of the samples for a def inite time.