Method of producing crystalline polycarbonate powders
A method of preparing a partially crystalline polycarbonate powder, including: dissolving an amorphous polycarbonate in a halogenated alkane solvent to form a solution; combining the solution with a crystallizing non-solvent that is miscible with the halogenated alkane solvent, under high shear mixing conditions effective to form a partially crystalline polycarbonate precipitate having a D90 particle size of less than 150 micrometers; an average particle diameter of less than or equal to 100 micrometers, or an average particle diameter of 0 to 100 micrometers; and at least 20% crystallinity, or at least 25% crystallinity, or 25 to 35% crystallinity.
1. A method of preparing a partially crystalline polycarbonate powder, the method comprising:
dissolving an amorphous polycarbonate in a halogenated alkane solvent to form a solution;
combining the solution with a crystallizing non-solvent that is miscible with the halogenated alkane solvent, under high shear mixing conditions effective to form a partially crystalline polycarbonate precipitate having
a D90 particle size of less than 150 micrometers;
an average particle diameter of less than or equal to 100 micrometers; and
at least 20% crystallinity;
wherein the crystallizing non-solvent is acetone, methyl ethyl ketone, or a combination comprising at least one of the foregoing.
2. The method of claim 1 , further comprising:
removing the halogenated alkane solvent and the crystallizing non-solvent from the precipitate; and
optionally, drying the precipitate.
3. The method of claim 1 , wherein the halogenated alkane solvent comprises dichloromethane, chloroform or a combination comprising at least one of the foregoing.
4. The method of claim 1 , wherein the crystallizing non-solvent is acetone.
5. The method of claim 1 , wherein the high shear mixing comprises mixing at a speed of 2,000 to 20,000 rpm.
6. A partially crystalline polycarbonate powder prepared by the method of claim 1 .
7. A powder composition comprising a partially crystalline polycarbonate powder having
a D90 particle size of less than 150 micrometers;
an average particle diameter of 10 to 100 micrometers; and
25 to 35% crystallinity.
8. A method of preparing a three-dimensional article, the method comprising:
providing a powder composition comprising a partially crystalline polycarbonate powder made by the method of claim 1 ; and
powder bed fusing the powder composition to form a three-dimensional article.
9. A method of preparing a three-dimensional article, the method comprising:
providing a powder composition comprising a partially crystalline polycarbonate powder having
a D90 particle size of less than 150 micrometers;
an average particle diameter of less than or equal to 100 micrometers; and
at least 20% crystallinity; and
powder bed fusing the powder composition to form a three-dimensional article.
10. The method of claim 1 , comprising adding 0.05% to 5% of a flow agent to the powder composition.
11. The method of claim 10 , wherein the flow agent comprises a hydrated silica, amorphous alumina, a glassy silica, a glassy phosphate, a glassy borate, a glassy oxide, titania, talc, mica, a fumed silica, kaolin, attapulgite, calcium silicate, alumina, and magnesium silicate or a combination comprising at least one of the foregoing.
12. The method of claim 1 , comprising adding a reinforcing agent to the powder composition.
13. The method of claim 8 , wherein the powder bed fusing comprises selective laser sintering.
14. A three-dimensional article made by the method of claim 8 , comprising a plurality of fused layers.
15. The three-dimensional article of claim 14 , comprising at least five fused layers.
16. The method of claim 1 , wherein the amorphous polycarbonate is a non-halide polycarbonate homopolymer or a poly(carbonate-siloxane) polymer, or a combination comprising at least one of the foregoing.
17. A powder composition of claim 7 , wherein the partially crystalline polycarbonate powder is a non-halide polycarbonate homopolymer or a poly(carbonate-siloxane) polymer, or a combination comprising at least one of the foregoing.
18. A method of preparing a three-dimensional article of claim 9 , wherein the partially crystalline polycarbonate powder is a non-halide polycarbonate homopolymer or a poly(carbonate-siloxane) polymer, or a combination comprising at least one of the foregoing.
19. The method of claim 1 , wherein the partially crystalline polycarbonate precipitate has
a D90 particle size of less than 150 micrometers;
an average particle diameter of 10 to 100 micrometers; and
25 to 35% crystallinity.