Calcium complexation by low molecular weight dicarboxycellulose in aqueous solution

Carbohydrate polymers having the ability to complex calcium ions are of commercial interest. The effects of molecular weight and neighbouring carboxylate functional groups on a cellulose chain have been reported in this paper. High molecular weight sodium carboxymethylcellulose (viscosity of 2% solution 12 cP) was found to be marginally superior to low molecular weight sodium dicarboxycellulose (viscosity of 2% solution 1.1 cP) in its calcium complexing ability. Thus the sterically favourable effects of the neighbouring carboxylate groups can be offset by viscosity effects; both these are therefore important parameters in deciding the calcium complexing ability of a polymer.