Periodate oxidation of cellulose at elevated temperatures using metal salts as cellulose activators

The birch cellulose is effectively oxidized to the dialdehyde cellulose (DAC) at elevated temperatures by sodium periodate. Even though periodate decomposes at 55 °C and above with time, higher temperatures can be used if the oxidation time is sufficiently short and it has now been shown that temperatures up to 85 °C can be used during the oxidation. Lithium chloride can be used to further improve the oxidation efficiency. Other metal salts, such as calcium chloride can be used as well. These conditions provides possibility to use a lower amount of periodate to obtain high aldehyde contents in DAC.