Anomalous swelling behavior has been observed in interpenetrating polymer n
etworks (IPNs) gel composed of poly (N-isopropylacrylamide) (PNIPAIM) and p
oly(acrylic acid) (PAA). Calorimetric endotherms, FT-IR (Fourier transform-
infrared) spectra and compression modulus show that the molecular interacti
on such as hydrogen bond and hydrophobic interaction serve-as a driving for
ce which takes place with an anomalous swelling behavior. (C) 1998 Elsevier
Science Ltd. All rights reserved.