Radical crosslinking

Photopolymerization is initiated by free radicals which are produced by the decomposition of a photoinitiator upon exposure to visible light and UV. The free radicals react with hydrogels precursors bearing polymerizable groups.

Figure 1. Radical crosslinked polymers. Polymers are shown in grey.

To allow radical crosslinking, acrylate or methacrylate moieties should be added to the polymer. These double bonds moieties will be activated by the free radical and form a linkage between adjacent polymers.