Poly (diallyldimethylammonium chloride) (PolyDADMAC) is one of typical polyelectrolytes having versatile applications in food

medicine

water treatment and other industries．The polyDADMAC hydrogel is transparent and has good water swelling properties

but it’s mechanical properties are quite poor

which limit its use．In order to overcome its poor mechanical properties

the copolymers of poly(DADMAC-AA) were synthesized by radiation copolymerization．The gel strength and solution properties of the hydrogels were studied．It was found that an increase of the total concentration of monomers and the molar ratio of AA would improve the mechanical strength and increase the gel fraction of synthesized hydrogels．The compositions of copolymers were consistant with the molar ratios of DADMAC and AA added in the original feed solutions according to results of infrared spectrum studies and elemental analysis．The swelling ratios of hydrogels decreased with the increase of molar ratio of AA．When DADMAC :AA was 1:2

the swelling measurements showed that the copolymer hydorgels may exhibit the properties of polyampholytes

which were reflected by their absorption of Re(Ⅶ) in aqueous solutions under different pH values．