Sueprabsorbents poly(acrylic acid/acrylamide) (PAAM) are prepared from partly neutralized acrylic acid(AA) and acrylamide(AM) by inverse suspension copolymerization. The influence of some main factors on its absorbency such as mol ration and neutralization of the monomers
the mass concentrations of the crosslinker
the initiator
and the initial temperature and the reaction time is discussed in detail. And then the structure and thermal property of PAAM are tested by FTIR and TGA. The optimum formula is obtained as follow:the mass concentration of all monomers (w) is 30%
the neutralized degree (N) is 75%
mol ratio of acrylic acid(AA) and acrylamide(AM) is 7:3
the mass concentrations of the crosslinker(NMBA)
the initiator(KPS) and the dispersing agent relative to all total monomers mass are 0.065%
0.7% and 0.5%
respectively
the drop-additive rate of the monomers solution is 2-3ml/min
the polymerizarion temperature and time are 70℃and 1.5h. The maximum absorbencies of PAAM in distilled water and in 0.9%NaCl solution under the optimum formula are 1300g/g and 93g/g. The thermal stability of PAAM before 320℃ is good.