Structural and rheological properties of methacrylamide modified gelatin hydrogels

Dynamic shear oscillation measurements at small strain were used to charact erize the viscoelastic properties and related differences in the molecular structure of hydrogels based on gelatin methacrylamide. Gelatin was derivat ized with methacrylamide side groups and was subsequently cross-linked by r adical polymerization via photoinitiation. The light treatment of methacryl amide gelatin solutions resulted in the production of hydrogel films with h igh storage modulus (G'). Mechanical spectra and thermal scanning rheology of the obtained hydrogels are described. The temperature scan of the networ k below and above melting point of gelatin allowed us to identify the respe ctive contributions of chemical and physical cross-linkage to the hydrogel elastic modulus. The results indicate that the rheological properties of th e gelatin-based hydrogels can be controlled by the degree of substitution, polymer concentration, initiator concentration, and UV irradiation conditio ns.