Fig. 5.

Schematic illustration of the influence of water on the crosslinking structure formed by free-radical/cationic ring-opening hybrid polymerization. Blue color represents chains of polymethacrylate; Black color represents chains of siloxane-containing polyether. A) After photo curing, crosslinking network was formed by poly-methacrylates from free-radical polymerization with enhanced crosslinking structure by chain transfer reaction between epoxy and hydroxyl groups in methacrylates (B, zooming in). C) When water was added to the hybrid formulations, water will compete with hydroxyl groups in methacrylates, and reduce the crosslinking density, forming a new phase (siloxane-containing polyether phase: black color).