THERMOREVERSIBLE HYDROGEL BASED ON RADIATION-INDUCED COPOLYMERIZATIONOF POLY(N-ISOPROPYL ACRYLAMIDE) AND POLY(ETHYLENE OXIDE)

Thermoreversible copolymer hydrogel based on poly(ethylene oxide) and poly(hi-isopropyl acrylamide) has been prepared by gamma-radiation tec hnique. The utility of C-13 n.m.r. spectroscopy in elucidating the str ucture and copolymer composition has been demonstrated. The volume tra nsition as a function of temperature in these copolymers has been stud ied by swelling ratio measurements. Unlike poly(ethylene oxide) homopo lymer gel, the copolymer gels show first order volume transition in th e temperature range of 35-40 degrees C. These gels are easy to synthes ise in any shape and size and are found to be having good mechanical s trength even in the fully swollen state. They can have potential appli cations in controlled drug delivery, bioseparations and biomedical fie lds. (C) 1998 Elsevier Science Ltd. All rights reserved.