Preparation and Study on Kaoline/Citric Acid Complex Superabsorbent Resin

A superabsorbent resin was synthesized by aqueous solution polymerization with acrylic acid, acrylamide, kaoline and citric acid as substrates, N, N- methylene bisacrylamide(NMBA) as crosslinker, and potassium persulfate(KPS) as initiator. The influences of mass ratio of kaoline and citric acid, the monomer ratio, the content of crosslinking agent, the amount of initiator, reaction temperature and neutralization degree of acrylic acid were studied. The results show that the optimal reaction conditions are as follows. The mass ratio of kaoline to citric acid was 1: 2, the mass ratio of acrylic acid to acrylamide was 4: 1, the amount of crosslinker was 0.06%, the amount of initiating agent was 0.2%, the reaction temperature was 70 ℃, and the neutralization degree of acrylic acid was 65%. Under such conditions, absorbency of the resin in distilled water and Na Cl solution were 965 and 105 g·g-1, respectively.