effect of cross-linker types on properties of cross-linked poly (acrylic acid) as the superabsorbent

The monomer of acrylic acid (aa) was polymerized in presence of two crosslinking agent# polymerization was performed in aqueous xanthan solution# n, n′-hexane-1, 6-dilbisprop-2-enamide (ms) or 1,4-butandioldimethacrylate (bdod) was used as the cross-linking agent in various ratio of ms/bdod (100/0, 75/25, 50/50, 25/75, and 0/100)# polymerization was performed in an aqueous xanthan solution (1% wt)# prepared crosslinker and semi-interpenetrating polymer networks (semi-ipns) evaluated by fourier transform infrared (ft-ir), proton nuclear magnetic resonance spectroscopy (1h nmr), x-ray diffraction (xrd) and thermogravimetric (tga) analyses# the results of tga showed that the thermal resistance of hydrogels increased with increasing bdod to ms ratio in content of crosslinker# in addition, the results of the swelling test showed that with increasing ms content in the cross-linker, the swelling rate increased in various ph of environment# but the swelling ratio is higher in alkaline environments to other phs for all samples# the behavioral differences in all tests can be due to the urethane groups in the cross-linker structure# the resulting hydrogels can be used in tissue engineering, dye and effluent absorption, drug delivery and synthetic cartilage#