Polyacrylate superabsorbents were prepared by in situ aqueous solution polymerization in a polyethylene bag, which was submerged in a water bath. The influence of the initiator content, bath temperature, isopropanol content, initial monomer concentration, and crosslinker content (Cc) on water absorbency (Q) were investigated. The temperature change of the monomer mixture during polymerization was also analyzed. Increase of the chain ends in networks resulting from decrease of the molecular weight in free-radical polymerization causes an increase of the water absorbency of superabsorbents and also reduces the crosslinking efficiency. The results are in conformity with the classical network theory. An empirical relation of Q = 2.45 Cc(-0.600) was obtained and the validity of Flory＇s swelling equation was confirmed indirectly. (C) 2000 John Wiley & Sons, Inc.