Iodine-Incorporated Copolymer of Methyl Methacrylate andN-Vinylpyrrolidone. I. Synthesis and Characterization

Methyl methacrylate and N-vinylpyrrolidone were copolymerized in an organic solvent using peroxide initiator and gamma radiation. The copolymers were treated with different weight percentages of molecular iodine in a homogeneous solution of dichloromethane. Iodine was found to be strongly attached to the polymer backbone, and only a negligible amount of free iodine could be extracted from the sample with as high as 40% iodine content. The copolymers of methyl methacrylate and N-vinylpyrrolidone prepared under different conditions showed a marked difference in their swelling behavior and thermal stability. The percent swelling and overall thermal stability of the samples decreased after incorporation of iodine into the polymer. The FT-IR, 1H-NMR, thermogravimetric data, and intrinsic viscosity of the copolymers and their iodine adducts are discussed. The results suggest the presence of specific interactions between the pyrrolidone group and iodine.