Fast Synthesis of Starch Based Composite Superabsorbent Polymer by Microwave Method and Its Swelling Properties

The starch based ionic and nonionic composite superabsorbent polymer( SAP) was synthesized efficiently under microwave irradiation by using cassava starch,partially neutralized acrylic acid and acrylamide as raw materials. With water absorption as index,the effects of the main synthetic technologies and swelling conditions on the swelling properties were investigated. The functional groups and morphology of the samples were characterized by means of FTIR and SEM,respectively. It was found that SAP had a porous structure. The SAP with an equilibrium absorbency of 445. 2 g / g in pure water was prepared under the conditions of microwave power 400 W and reaction time 2 min. Moreover, the swelling processes of SAP at different temperature were in accordance with the first-order dynamics, and the swelling rate increased with the increase of temperature. The swelling of SAP was pH and salt dependent. Furthermore,the swelling of SAP in organic solution was affected by the solubility parameter of solution,and the greater the difference of solubility parameter between organic solution and water was,the greater the swelling loss.