Modification of carboxymethyl cellulose through oxidation

The periodate oxidation reaction of carboxymethyl cellulose involve the primary and secondary hydroxyl groups of the pyranose ring. The reaction is accompanied by the opening of the pyranose ring and resulting product is dialdehyde carboxymethyl cellulose along with some hydrated forms. In this process the glucosidic bond becomes weaker; the formation of carboxyl groups induces a depolymerization, thus reducing the polymerization degree and the physical and mechanical strength of the material. The reaction has been has been carried out at pH 3.5, temperature 45 °C for 0.5–4 h.