Preparation and characterization of co hydrogel (Vinyl Pyrrolidone- Methacrylic acid) by free radical polymerization method

Hydrogels are three dimensional polymers that do not dissolve in water, but they swell. One of the most important physical properties of hydrogels is their swelling in water [1]. Polyvinylpyrrolidone is widely used for its biocompatibility behavier [2]. Methacrylic acid also has many uses due to its COOH group. In this project, co hydrogel (vinyl pyrrolidone-methacrylic acid) was prepared by using free radical polymerization at 65 ° C for 5 hours and45 minutes using AIBN as a initiator and methylene bis acrylamide as a crosslinking agent. Then, at different pH and different temperatures and intensity of different ions, the maximum swelling at pH = 12 and in the ratio 1: 1,8000%, and the minimum swelling at pH=12 in ratio 1:2 was obtained. To identify the structure we use FTIR and for thermal identification we use T.G.A. And the maximum degradation for these hydrogels was at 75 ° C due to the high swelling rate.