Curable polymeric compositions
Compounds and compositions are provided which are useful in additive printing, particularly additive printing techniques such as stereolithography (SLA), wherein a composition of one or more photocurable compounds, such as a compound with multiple ethylenically unsaturated groups and a compound with multiple thiol groups, is photopolymerized, optionally in the presence of two or more thermocurable compounds which are reactive with one another and are subjected to thermopolymerization, to form a manufactured article in solid form.
1 . A composition comprising:
a first organic compound (polySH) having multiple thiol groups (SH), wherein the first organic compound is bioabsorbable, and wherein polySH is a macromer;
a second organic compound (polyEU) having multiple ethylenically unsaturated groups (EU), wherein the second organic compound is bioabsorbable, and wherein polyEU is a macromer;
having an SH to EU equivalents ratio of X:Y, where X ranges from 25-75 and Y ranges from 75-25 and the sum of X and Y is 100;
a photoinitiator, wherein the photoinitiator is in a total concentration of less than 1.0 wt %; and
optionally a stabilizer;
wherein the composition is bioabsorbable; and
wherein the composition is substantially free of monomers.
2 . The composition of claim 1 wherein EU of polyEU is acrylate, methacrylate or norbornenyl.
3 . The composition of claim 1 wherein at least one polyEU and polySH further has multiple ester groups and multiple carbonate groups, where optionally polyEU has both multiple ester groups and multiple carbonate groups, or where optionally both of polySH and polyEU further have both multiple ester groups and multiple carbonate groups.
4 . The composition of claim 1 wherein at least one of polySH and polyEU further has multiple carbonate groups and multiple urethane groups, where optionally polyEU has both multiple carbonate groups and multiple urethane groups, or where optionally both of polySH and polyEU further have both multiple carbonate groups and multiple urethane groups.
5 . The composition of claim 1 which is free of volatile materials having a boiling point of less than 110° C.
6 . A composition comprising a photochemically cured reaction product of the composition of claim 1 .
7 . The composition of claim 6 which is a solid at 50° C.
8 . An additive manufacturing process comprising:
(a) providing a vat containing a first composition of claim 1 ;
(b) directing actinic radiation from a light source into the first composition in the vat, where the actinic radiation is effective to induce polymerization of components of the composition so as to form a second composition; and
(c) forming a solid article comprising the second composition.
9 . The composition of claim 1 , wherein polySH is water soluble.
10 . The composition of claim 1 , wherein polySH has a molecular weight of greater than 1,000 g/mol.
11 . The composition of claim 1 , wherein polyEU is water soluble.
12 . The composition of claim 1 , wherein polyEU has a molecular weight of greater than 1,000 g/mol.
13 . The composition of claim 1 , wherein the multiple SH of polySH is selected from 2, 3, and 4.
14 . The composition of claim 1 , wherein the multiple EU of polyEU is selected from 2, 3, and 4.
15 . The composition of claim 1 , wherein the composition is anhydrous.
16 . The composition of claim 1 , wherein the composition is fluid at a temperature of from 18° C. to 22° C.