Abstract: The invention provide a class of chain-extended polysiloxane crosslinkers which comprises (1) at least two polylsiloxane segments, wherein each pair of adjacent polysiloxane segments is linked by one divalent organic radical which includes at least one pendant hydrophilic group (hydroxyl and/or carboxyl groups) or at least one dangling hydrophilic polymer chain and a di-thioether linkage —S-DR-S— in which DR is a divalent organic radical; and (2) two terminal ethylenically unsaturated groups. The present invention is also related to a polymer comprising crosslinking units derived from chain-extended polysiloxane crosslinker of the invention and to ophthalmic lenses comprising such a polymer.

Abstract: The invention provide a class of chain-extended polysiloxane crosslinkers which comprises (1) at least two polylsiloxane segments, wherein each pair of adjacent polysiloxane segments is linked by one divalent organic radical which includes at least one pendant hydrophilic group (hydroxyl and/or carboxyl groups) or at least one dangling hydrophilic polymer chain and a di-thioether linkage —S-DR-S— in which DR is a divalent oranic radical; and (2) two terminal ethylenically unsaturated groups. The present invention is also related to a polymer comprising crosslinking units derived from chain-extended polysiloxane crosslinker of the invention and to ophthalmic lenses comprising such a polymer.

Abstract: The invention provide a class of chain-extended polysiloxane crosslinkers which comprises (1) at least two polysiloxane segments, wherein each pair of adjacent polysiloxane segments is linked by one divalent organic radical which includes at least one pendant hydrophilic group (hydroxyl and/or carboxyl groups) or at least one dangling hydrophilic polymer chain and a di-thioether linkage —S-DR-S— in which DR is a divalent organic radical; and (2) two terminal ethylenically unsaturated groups. The present invention is also related to a polymer comprising crosslinking units derived from chain-extended polysiloxane crosslinker of the invention and to ophthalmic lenses comprising such a polymer.

Abstract: The present invention provides an amphiphilic polysiloxane prepolymer which comprises hydrophilic monomeric units derived from at least one hydrophilic vinylic monomer, polysiloxane crosslinking units derived from at least one polysiloxane crosslinker having at least two terminal ethylenically-unsaturated groups, dangling polysiloxane chains each of which is terminated with one ethylenically unsaturated group, and chain-transfer units derived from a chain transfer agent other than a RAFT agent. A prepolymer of the invention is suitable for making hydrogel contact lenses. The present invention is also related to hydrogel contact lenses made from an amphiphilic polysiloxane prepolymer of the invention and to processes for preparing an amphiphilic polysiloxane prepolymer of the invention and for making silicone hydrogel contact lenses.

Abstract: The invention provide a class of chain-extended polysiloxane crosslinkers which comprises (1) at least two polysiloxane segments, wherein each pair of adjacent polysiloxane segments is linked by one divalent organic radical which includes at least one pendant hydrophilic group (hydroxyl and/or carboxyl groups) or at least one dangling hydrophilic polymer chain and a di-thioether linkage —S-DR—S— in which DR is a divalent organic radical; and (2) two terminal ethylenically unsaturated groups. The present invention is also related to a polymer comprising crosslinking units derived from chain-extended polysiloxane crosslinker of the invention and to ophthalmic lenses comprising such a polymer.

Abstract: The present invention provides an amphiphilic polysiloxane prepolymer which comprises hydrophilic monomeric units derived from at least one hydrophilic vinylic monomer, polysiloxane crosslinking units derived from at least one polysiloxane crosslinker having at least two terminal ethylenically-unsaturated groups, dangling polysiloxane chains each of which is terminated with one ethylenically unsaturated group, and chain-transfer units derived from a chain transfer agent other than a RAFT agent. A prepolymer of the invention is suitable for making hydrogel contact lenses. The present invention is also related to hydrogel contact lenses made from an amphiphilic polysiloxane prepolymer of the invention and to processes for preparing an amphiphilic polysiloxane prepolymer of the invention and for making silicone hydrogel contact lenses.