Patent ID: 8557940

Claim:
An amphiphilic branched prepolymer which is obtained by: (i) polymerizing a polymerizable composition to obtain an amphiphilic branched polysiloxane copolymer, wherein the polymerizable composition comprises (a) from about 10% to about 94% by weight of a partially ethylenically-functionalized polysiloxane, wherein the partially ethylenically-functionalized polysiloxane is a mixture of reaction products obtained by reacting a first ethyleincally functionalizing vinylic monomer having a first reactive functional group with a functional polysiloxane compound having two or more second reactive functional groups at a molar equivalent ratio, R Equivalent , of from about 40% to about 95%, wherein each first reactive functional group reacts with one second reactive functional group in the presence or absence of a coupling agent to form a covalent bond or linkage, wherein the mixture of reaction product comprises at least one polysiloxane crosslinkers having at least two ethylenically unsaturated groups and at least one polysiloxane vinylic monomer or macromer having at least one second reactive functional group and at least one ethylenically unsaturated group, (b) at least one hydrophilic vinylic monomer, (c) optionally a hydrophobic vinylic monomer, (d) a chain transfer agent other than a RAFT agent, wherein the chain transfer agent optionally including a third reactive functional group, and (e) a free-radical initiator; and (ii) ethylenically functionalizing the amphiphilic branched polysiloxane copolymer by reacting it with a second ethylenically functionalizing vinylic monomer having a fourth reactive functional group which reacts with one second or third reactive functional group in the presence or absence of a coupling agent to form a covalent linkage, thereby forming the amphiphilic branched polysiloxane prepolymer.