Preparation of poly(N, N-dimethy-lacrylamide)/graphene oxidenanocomposite hydrogel with high mechanical strength

Nanocomposite hydrogels with high mechanical strength were prepared by in situ polymerization in graphene oxide aqueous suspension, using N, N-dimethylacrylamide (DMA) as monomer and N, N-cystaminebisacrylamide (CBA) as crosslinker. The effect of the content of graphene oxide (GO) and CBA on the properties of the hydrogel was investigated. It is found that tensile strength, compressive strength and thermal properties of the hydrogel increase, while the equilibrium swelling ratio of the hydrogel decreases with increasing the content of GO or CBA. The grafting efficiency of PDMA on the GO surface was measured by TGA, for the disulfide bond of the cross linker, i.e., CBA can be fractured by reducing agent. The result shows that GO was not simply physically blended in the composite hydrogel, in fact, it acts as crosslinking agent, so the PDMA/GO nanocomposite hydrogel has excellent tensile strength and compressive strength.