Gamma-radiation-induced graft copolymerization of acrylamide onto crosslinked poly(N-vinylpyrrolidone)

Crosslinked poly(N-vinylpyrrolidone) (PVPy) beads were irradiated with γ-rays in air from a 60Co source. Preirradiated beads were grafted with polyacrylamide by refluxing with acrylamide in water or dioxane. Conditions for optimum grafting were determined under a variety of reaction parameters, such as the total dose, duration, and temperature of heating, and the molar concentration of acrylamide used. The effect of the addition of methanol to the aqueous medium during grafting was also studied. The pendant carboxamide groups of PVPy-g-polyacrylamide were transformed into amino, aminoethylamido, and hydrazide functionalities terminating in primary amino or hydrazido groups. These provide sites for immobilizing proteins through their amino or carboxyl groups and, also, handles for attaching reagent molecules.