An efficient preparation method for superabsorbent polymers

High water-absorbent polyacrylates could be prepared by concentrated aqueou s solution polymerization within a short time period, heating the monomer m ixture by water bath. The influences of initiator content, bath temperature , crosslinker content (Cc), and degree of neutralization on water absorbenc y (Q) were investigated. The temperature changing of the monomer mixture du ring polymerization was thoroughly analyzed. The increase of initiator cont ent as well as the increase of bath temperature results in the increase of water absorbency and reduces the crosslinking efficiency. The results are i n conformity with Flory's network theory and also illustrate that lower cro sslinking efficiency occurs when the polymerization rate is faster. An empi rical relation of Q = 1.40 Cc(-0.665) is obtained and its exponent is very close to -0.6 in a derived relation. (C) 1999 John Wiley & Sons, Inc.