Chain-extended polysiloxane crosslinkers with dangling hydrophilic polymer chains

A soluble amphiphilic prepolymer, which is obtained by:

• first polymerizing a polymerizable composition including
• (1) at least one chain-extended polysiloxane crosslinker,
• (2) at least one hydrophilic vinylic monomer,
• (3) a chain transfer agent with or without a first reactive functional group other than a thiol group and/or a vinylic monomer having a second reactive functional group other than an ethylenically unsaturated group,
• (4) optionally a hydrophobic vinylic monomer, and
• (5) optionally a polymerizable UV-absorbing agent, to form an intermediary copolymer;
• and
• then ethylenically functionalizing the intermediary copolymer with an ethylenically functionalizing vinylic monomer having a third reactive functional group capable of reacting with the first or second reactive functional group to form a linkage in a coupling reaction in the presence or absence of a coupling agent to form the prepolymer, wherein the first, second and third reactive functional groups independent of each other are selected from the group consisting of amino group, hydroxyl group, carboxyl group, acid halide group, azlactone group, isocyanate group, epoxy group, aziridine group, and combination thereof
• wherein the linear chain-extended polysiloxane crosslinker comprises (a) two terminal ethylenically unsaturated groups, (b) at least two polysiloxane segments, and (c) at least one dangling hydrophilic polymer chain covalently attached to a divalent organic radical separating said at least two polysiloxane segments, wherein the linear chain extended polysiloxane crosslinker is as set forth by formula (I)
• in which
• D0, D1, D2 and D3 independently of one another are a divalent group of formula (II)
• in which G5 is as defined below, A1, A2 A3, and A4 independent of one another are a direct bond, a linear or branched C1-C10 alkylene divalent radical, —(CH(R″)CH2O)r1—CH(R″)CH2— in which R″ is H or methyl and r1 is an integer of 1 to 20, or a C1-C7 alkyleneoxy C1-C7 alkylene divalent radical, R1, R2, R3, R4, R5, R6, R7, R8, R1′, R2′, R3′, R4′, R5′, R6′, R7′, and R8′ independently of one another are C1-C8-alkyl, C1-C4 alkyl-substituted phenyl, C1-C4-alkoxy-substituted phenyl, fluoro(C1-C18-alkyl), or -alk-(OCH2CH2)n—OR9 in which “alk” is C1-C6-alkylene divalent radical, R9 is C1-C6 alkyl and n is an integer from 1 to 20, a1 is an integer of 0 to 8, m1 and p1 independently of each other are an integer of from 0 to 150, (m1+p1) is from 2 to 150, m2 and p2 independent of each other are an integer of from 0 to 150 and (m2+p2) is from 2 to 150 if a1 is not zero;
• e1, e2, t1, t2, and t3 independent of one another are an integer of 0 or 1;
• υ1, υ2 and υ3 independent of one another are an integer of from 0 to 5 provided that (υ1+υ2+υ3)≧1;
• ω1, ω2 and ω3 independent of one another are an integer of from 0 to 20 provided that (ω1+ω2+ω3) is an integer of 1 to 20;
• L1, L2 and L3 independent of one another is a direct bond,
• in which R12 is hydrogen or C1-C4 alkyl;
• L1′, L2′ and L3′ independent of one another is a direct bond or
• in which R12 is as defined above, Y is —O— or —NR′— in which R′ is hydrogen or C1-C8 alkyl, and Y is linked to T1, T2 or T3;
• G0, G1, G1′, G1″, G2, G2′, G2″, G3, G3′, G3″, G4, and G5 independent of one another are a direct bond or a divalent radical of —Z1—X1—Z2—X2—Z3—X3—Z4—, in which X1, X2, and X3 independent of one another are a linkage selected from the group consisting of a direct bond, —O—, —NR′—, —C(O)—NR′—, —NR′—C(O)—, —O—C(O)—NH—, —NH—C(O)—O—, —NR′—C(O)—NH—, —NH—C(O)—NR′—, —S—, —C(O)—O—, —O—C(O)—, —NH—C(O)—NH—Z0—NH—C(O)—NH—, —O—C(O)—NH—Z0—NH—C(O)—O—, —O—C(O)—NH—Z0—NH—C(O)—NH—, and —NH—C(O)—NH—Z0—NH—C(O)—O—, Z0 is a linear or branched C2-C12 alkylene divalent radical or a C5-C45 cycloaliphatic or aliphatic-cycloaliphatic divalent radical optionally containing therein one or more linkages of —O—, —NR′—, —S— and —C(O)—, R′ is H or C1-C0 alkyl, Z1, Z2, Z3, and Z4 independent of one another are a direct bond, a linear or branched C1-C18 alkylene divalent radical optionally containing therein one or more linkages of —O—, —NR′—, —S— and —C(O)—, a C1-C7 alkyleneoxy C1-C7 alkylene divalent radical, a divalent radical of —(CH(R″)CH2O)r1—CH(R″)CH2— in which R″ and r1 are as defined above, an unsubstituted phenylene divalent radical, C1-C4 alkyl substituted phenylene divalent radical, C1-C4 alkoxy substituted phenylene divalent radical, a C5-C45 cycloaliphatic or aliphatic-cycloaliphatic divalent radical optionally containing therein one or more linkages of —O—, —NR′—, —S— and —C(O)—, a C6-C24 aromatic or araliphatic divalent radical, or combinations thereof;
• R10 and R11 independent of each other are hydrogen or C1-C4 alkyl;
• is a linear or 3-arm hydrophilic polymer chain that comprises at least about 60% by weight of one or more hydrophilic monomeric units;
• and
• T1, T2 and T3 independent of one another are a linear or branched C2-C24 aliphatic trivalent radical, a C5-C30 cycloaliphatic or aliphatic-cycloaliphatic trivalent radical, a C4-C30 aliphatic-heterocyclic trivalent radical including one or more oxygen or nitrogen atoms, or a C3-C24 aromatic or araliphatic trivalent radical.