Swelling and Viscoelastic Properties of Cellulose-Based Hydrogels Prepared by Free Radical Polymerization of Dimethylaminoethyl Methacrylate in Cellulose Solution.

The grafting of a stimuli-responsive polymer (poly(dimethylaminoethyl methacrylate)) onto cellulose was achieved by performing free radical polymerization of a vinyl/divinyl monomer in cellulose solution. The grafting and crosslinking efficiency in the material have been increased by subsequent irradiation of the samples with ionizing radiation (doses of 10, 30, or 100 kGy). The relative amount of poly(dimethylaminoethyl methacrylate) in the prepared hydrogels was determined by infrared spectroscopy. The swelling behavior of the hydrogels was studied thoroughly, including microgelation extent, equilibrium swelling, and reswelling degree, as well as the dependence on the gelation procedure. The dynamic viscoelastic behavior of prepared hydrogels was also studied. The tan δ values indicate a solid-like behavior while the obtained hydrogels have a complex modulus in the range of 14-39 kPa, which is suitable for hydrogels used in biomedical applications. In addition, the incorporation of Ag particles and the adsorption of Fe 3+ ions were tested to evaluate the additional functionalities of the prepared hydrogels. It was found that the introduction of PDMAEMA to the hydrogels enhanced their ability to synthesize Ag particles and absorb Fe 3+ ions, providing a platform for the potential preparation of hydrogels for the treatment of wounds.