Polyimide microparticles
A method for producing polyimide microparticles may comprise: combining a diamine and a dianhydride in a first dry, high boiling point solvent; reacting the diamine and the dianhydride to produce a mixture comprising poly(amic acid) (PAA) and the first dry, high boiling point solvent; emulsifying the mixture in a matrix fluid that is immiscible with the first dry, high boiling point solvent using an emulsion stabilizer to form a precursor emulsion that is an oil-in-oil emulsion; and heating the precursor emulsion during and/or after formation to a temperature sufficient to polymerize the PAA to form the polyimide microparticles.
1. A composition comprising:
microparticles comprising a polyimide and an emulsion stabilizer forming a coating upon an outer surface of the microparticles;
wherein the emulsion stabilizer comprises oxide nanoparticles.
2. The composition of claim 1 , wherein the polyimide comprises a reaction product of a diamine and a dianhydride.
3. The composition of claim 1 , wherein the oxide nanoparticles comprise silica nanoparticles.
4. The composition of claim 1 , wherein the microparticles have a circularity of about 0.9 to about 1.0.
5. The composition of claim 1 , wherein the microparticles have an angle of repose of about 25° to about 45°.
6. The composition of claim 1 , wherein the microparticles have a sintering window of about 15° C. to about 35° C.
7. The composition of claim 1 , wherein the microparticles have a D10 of about 0.5 μm to about 50 μm, a D50 of about 10 μm to about 200 μm, and a D90 of about 50 μm to about 300 μm, wherein D10<D50<D90.
8. The composition of claim 1 , wherein the microparticles have a diameter span of about 0.2 to about 10.
9. The composition of claim 1 , wherein the microparticles have a Hausner ratio of about 1.0 to about 1.5.
10. The composition of claim 1 , wherein the microparticles have a bulk density of about 0.2 g/cm 3 to about 0.8 g/cm 3 , a BET surface area of about 30 m 2 /g to about 500 m 2 /g, or any combination thereof.
11. The composition of claim 1 , wherein the microparticles have a porous morphology.
12. A method comprising:
depositing the composition of claim 1 upon a surface; and
once deposited, heating at least a portion of the microparticles to promote consolidation thereof and form a consolidated body.
13. The method of claim 12 , wherein thermoplastic polymer particles are deposited upon the surface in combination with the microparticles comprising the polyimide.
14. The method of claim 12 , wherein heating takes place by selective laser sintering.