Synthesis and Characterization of N-maleyl Chitosan-Cross-Linked Poly(acrylamide)/Montmorillonite Nanocomposite Hydrogels

This paper reports a poly(acrylamide)/Montmorillonite (PAm/MMT) nanocomposite hydrogel with enhanced biodegradable and mechanical properties based on chitosan and nanoparticle montmorillonite (MMT). With biodegradable N-maleyl chitosan cross-linker, the nanocomposite hydrogel was prepared by the free radical polymerization among chitosan, acrylamide, and Na-montmorillonite in aqueous solution. The clay content varied from 0 to 10wt% (based on the monomer). The swelling kinetics, the mechanical property and enzymatic degradation of the nanocomposite hydrogels were investigated in detail. The results showed that the tensile strength (TS) of nanocomposite hydrogel films increased significantly with the addition of MMT. Compared with PAm hydrogel film without introduction of MMT, the TS of the nanocomposite films were approximately 85.7% and 102.3% increase with increasing amount of 3wt% and 5wt% Na-MMT. In characterization of swelling kinetics, the time of reaching the swelling equilibrium of hydrogel samples was affected slightly by varying the mass ratio of Am and Na-MMT. And the measurement of enzymatic degradation was also investigated in pepsin SGF solution at 37 degrees C.