POLY(N-VINYLPYRROLIDONE) HYDROGELS .1. RADIATION POLYMERIZATION AND CROSS-LINKING OF N-VINYLPYRROLIDONE

The effects of irradiation dose on the conversion of vinylpyrrolidone (VP) with various concentration and other characteristics such as Gela tion Dos (Dg), Degree of Swelling (DS) and Equilibrium Water Content ( EWC) have been investigated. Aqueous solution of vinylpyrrolidone with several concentrations such as 5, 10, 20, 40, 60, 80, and 100 Wt % we re irradiated by using gamma rays of Cobalt-60 source with a dose rate of 0. 139 Gy/s. After irradiation, parameters such as conversion of v inylpyrrolidone, gelation dose, degree of swelling, and equilibrium wa ter content were analyzed. Results show that the conversion of VP to P VP was a most 100 % at a dose of 2 kGy. The gelation dose of PVP depen ds on initial content of monomer. Degree of swelling of gels with conc entration of 10 % was 55 at the dose of 10 kGy and 30 at the dose of 4 0 kGy. The lowest value of degree of swelling is 15. At the range of i rradiation dose of 10 to 40 kGy the EWC of gel was found to be 98 to 9 4%.