Synthesis of Superabsorbent by Inverse Suspension Copolymrrization of AA and AMPS Initiated by APS-Na_2SO_3

Superabsorbent resins based on AA and AMPS were synthesized by inverse suspension copolymerization , in which APSNa2SO3 as initiator. The preferable conditions are: wAMPS=0.30, cAPSNa2SO3= 22.64 mmol·L 1,cMBAM=1.082 mmol·L 1, the temperature of copolymerization 50 ℃,neutralization degree of AA 80%, wOP4-PEG =0.003. Absorbency of the corresponding resin: Adeionized water=1 070 mL·g 1, Anormal water=220 mL·g 1,and its absorbabilty in normal saline is better than that of PAA or PAAAM(based on inverse suspension polymerization). Thermal stabability of the copolymer was slightly lower than that of poly(sodium acrylate) over 140 ℃, and the pure water retention ability equivalent to the later. Stabilzer concentration , different dispersion media and initiators affected the properties of the copolymer.