Photoinitiator modified polyacidic polymer

An initiator modified polyacidic polymer having a covalently bonded initiator compound, wherein the initiator modified polyacidic polymer contains 0.01 to 20 mole% covalently bonded initiator compound per 100 mole % of acidic groups of the initiator modified polyacidic polymer, wherein the initiator modified polyacidic polymer is a compound having repeating units of a following formula (I):

• wherein
• X, which may be a same or different, and independently represent OH, O—L—Z, or NH—L—Z,
• wherein
• L is a single bond or a divalent linker group, and
• Z is a covalently bonded initiator compound;
• Y is a hydrogen atom, COOH or a covalently bonded initiator compound;
• wherein the covalently bonded initiator compound is selected from the group of benzophenone, 1,2-diketones, 1,3 diketones, aromatic amines, and phosphines;
• k, l, m, n, o and p are independently integers of at least 0,
• k+l+m+n+o+p is at least 1;
• and
• at least one X is present which is not OH when Y is a hydrogen atom or COOH;
• wherein the polyacidic polymer has a weight average molecular weight of 1 to 300 kDa.

A method of forming a dental composition;

• said method comprising:
• mixing a composition comprising an initiator modified polyacidic polymer having a covalently bonded initiator compound with a reactive particulate filler to form the dental composition;
• wherein the initiator modified polyacidic polymer is a compound having repeating units of a following formula (I):
• wherein
• X, which may be a same or different, and independently represent OH, O—L—Z, or NH—L—Z,
• wherein
• L is a single bond or a divalent linker group, and
• Z is a covalently bonded initiator compound;
• Y is a hydrogen atom, COOH or a covalently bonded initiator compound;
• wherein the covalently bonded initiator compound is selected from the group of benzophenone, 1,2-diketones, 1,3 diketones, aromatic amines, and phosphines;
• k, l, m, n, o and p are independently integers of at least 0,
• k+l+m+n+o+p is at least 1;
• and
• at least one X is present which is not OH when Y is a hydrogen atom or COOH;
• wherein the polyacidic polymer has a weight average molecular weight of 1 to 300 kDa;
• wherein the initiator modified polyacidic polymer contains 0.01 to 20 mole % covalently bonded initiator compound per 100 mole % of acidic groups of the polyacidic polymer.