Yao, KD (reprint author), Tianjin Univ, Res Inst Polymer Mat, Tianjin 300072, Peoples R China.
A comparative study of the swelling behaviour of crosslinked chitosan (cr-CS) and its semi-interpenetrating polymer network (IPN) with poly(oxypropylene glycol) (cr-CS/PE semi-IPN) was carried out by DSC, NMR and positron annihilation lifetime spectroscopy (:PALS). The results reveal that cr-CS/PE semi-IPN containing hydrophobic moieties has more free volume for water at a definite water content and restricts its mobility less. NMR and PALS data indicate that water clusters coexist with water molecules hydrogen-bonded to the network at the beginning of swelling. (C) 1998 SCI.