EFFECT OF GAMMA-IRRADIATION AND TEMPERATURE ON THE STRUCTURE OF METALCHLORIDE TREATED POLY(ACRYLAMIDE)

The gamma-induced changes in the structure of poly(acrylamide) (PAAm) treated with metal chlorides were investigated by following the corres ponding variations in their ultraviolet spectra. Careful examination o f UV spectra revealed that irradiation of the specimens results in the appearance of an absorption peak at 275 nm whose intensity depends on the applied dose and the nature of the metal ions. This band is ascri bed to the formation of the carbonyl group. The results indicate that the dependence of the intensities of the band at 275 nm on the nature of the metal used provides strong evidence for the formation of metal polymer complexes. It was found that the pretreatment of PAAm with the appropriate concentration of ZnCl2, CoCl2, or NiCl2 reduces the effec ts of heating and the oxidation effects of gamma-irradiation. These re sults show that these metal ions can be used as stabilizers against th ermal degradation of PAAm in the temperature range up to 160-degrees-C . (C) 1993 John Wiley & Sons, Inc.