“…An example of cross-linking by radical polymerization is the synthesis of hydrogels of , a copolymerization of HEMA with the cross-linker EGDMA (ethylene glycol dimethacrylate) in the presence of AIBN (2,2′-azo-bis-isobutyronitrile), the radical initiator (Fig. Hydrogels can be obtained by radiation technique in a few ways, including irradiation of solid polymer (Nedkov and Tsvetkova 1994 ), monomer (in bulk or in solution) (Rosiak 1991 ), or aqueous solution of polymer (Kabanov 1998 20.1 Schematic representation of radical polymerization. Chemical cross-linking agents, such as acyl dichlorides (Fig.…”