An Environmentally-friendly Approach for Producing a Bio-superabsorbent based on Carboxymethyl Cellulose

Contamination of the environment by various pollutants has been one of the most important concerns of environmental scientists over the last decade. Water insoluble hydrophilic polymers with contaminants’ surface absorption potential are considered as new materials for the control and removal of pollutants. Carboxymethyl cellulose (CMC) powder with a purity of 87.7 % and 0.5 degrees of substitution (DS) was utilized in the current research project. The aim was to produce a superabsorbent through an environmentally-friendly approach based on bio-based materials. First, in order to insolubilize CMC powder, a wide range of temperature and time were experimented on among which combinations of temperatures of 165, 175 and 180 °C and time periods of 45, 60 and 90 minutes were selected, respectively. Then, a certain amount of heat-modified samples were weighed and dispersed in water and citric acid as a cross-linking agent was added with 0.1, 0.3, 0.5, 2, 3.5, 5, 10, 15 and 20 addition levels based on polymer weight. The samples were evaluated through the Tea Bag, Ionic Sensitivity, Absorption under load (AUL), Deformability and Swelling Kinetic tests. The results showed that heat treatment reduced the consumption of the crosslinking agent in which the highest absorption capacity was observed in low cross-linker addition levels in all tests.