Thermal and radiation chemical stabilities of some polymers after Cu(II) build-up

The interaction of polyacrylic acid (PAA), polysodium acrylate (PAANa), polyacrylamide (PAM) and acrylic acid–acrylamide copolymer P(AM-AA) with copper sulphate was studied to evaluate the thermal and radiation chemical stabilities of the resultant polymers which contained increasing quantities of Cu^{2 +} . It was found that the efficiency of the polymers toward Cu^{2 +} interaction, as determined by XRF, follows the order P(AM-AA) > PAM > PAANa. PAA was inactive, and no Cu^{2 +} ions were detected. Generally, the results obtained from TGA and DSC reveal that there is an improvement in the thermal stability when Cu^{2 +} is incorporated into the polymer matrix, but the amount of Cu^{2 +} bound to the polymeric chains does not correlate with their relative thermal stability. The degree of crystallinity estimated by X-ray diffraction also increases as Cu^{2 +} is incorporated into the polymer. In addition to the thermal stability, the radiation chemical stability of polymer with accumulated Cu^{2 +} was found to be very high, so that the percentage of Cu^{2 +} released from the crosslinked polymers was zero at radiation doses of up to 500 kGy. © 1999 Society of Chemical Industry