Biocompatible Tough Hydrogels via Micellar Copolymerization of NIPAM and Stearyl Acrylate: Synthesis and Characterization

Novel biocompatible tough hydrogels were prepared through free radical micellar polymerization of N-isopropylacrylamide (NIPAM) with ammonium persulphate (APS) as initiator, in which hydrophobic monomer stearyl acrylate (C18) underwent micellar polymerization in the presence of gelatin as emulsifier. FT-IR and DSC demonstrated the formation of co-polymer of NIPAM and C18. Swelling results indicated that hydrophobic polymer domains derived from C18 in aqueous medium acted as the physical crosslinking points by hydrophobic association. Uniaxial tensile test demonstrated the mechanical properties of hydrogels increased with increasing C18 and gelatin contents. The hydrogel exhibited low toxicity and promoted cell proliferation. The desirable toughness, low toxicity and the promoting effect of cell proliferation made the present hydrogels good candidates for tissue regeneration materials.