Hydrophilic simultaneous interpenetrating polymer network silicone hydrogels prepared by hybrid photopolymerization

Abstract

Hydrophilic silicone hydrogels have been prepared by UV-initiated free radical/cationic hybrid polymerization of acrylate oligomer polyethylene glycol diacrylate (PEGDA) and bifunctional vinyl ether terminated polydimethylsiloxane oligomer (VESi). PEGDA was shown to polymerize faster and more extensively than VESi, which was further consumed upon storage of the sample in the dark. The radical polymerization of PEGDA was affected by the oxygen inhibition effect, while the cationic polymerization of VESi was influenced by the atmosphere humidity. The presence of a nucleophile acetic acid could hinder the polymerization of VESi, but exerted less influence on the polymerization of PEGDA. The results of the contact angle measurements indicated that highly hydrophilic surfaces were obtained by the interpenetrating polymer network technique.