Effect of kappa-carrageenan on the properties of poly(N-vinyl pyrrolidone)/kappa-carrageenan blend hydrogel synthesized by gamma-radiation technology

A series of hydrogels in the form of rods were prepared from kappa-carragee nan (KC) and poly (N-vinyl pyrrolidone) (PVP) by gamma radiation with Co-60 gamma source at room temperature. The properties of the prepared hydrogels , such as the gel strength, gel fraction and swelling behavior were investi gated, Incorporation of KC into the PVP/water system increased obviously th e gel strength and equilibrium degree of swelling (EDS) of VP hydrogel. The experimental analyses showed that the crosslinking reaction of PVP was qui cker than the degradation of KC at a low dose (less than 30 kGy), and the d egradation of KC was inhibited in the PVP/KC mixture system. So an interpen etrating polymer network (IPN) hydrogel composed of PVP (a chemical crossli nking network) and KC (a physical crosslinking network) was proposed here. The existence of different classes of water in this IPN system was shown by water melting curves using DCS. (C) 2000 Elsevier Science Ltd. All rights reserved.