Preceramic 3D-printing monomer and polymer formulations
This disclosure provides resin formulations which may be used for 3D printing and thermally treating to produce a ceramic material. The disclosure provides direct, free-form 3D printing of a preceramic polymer, followed by converting the preceramic polymer to a 3D-printed ceramic composite with potentially complex 3D shapes. A wide variety of chemical compositions is disclosed, and several experimental examples are included to demonstrate reduction to practice. For example, preceramic resin formulations may contain a carbosilane in which there is at least one functional group selected from vinyl, allyl, ethynyl, unsubstituted or substituted alkyl, ester group, amine, hydroxyl, vinyl ether, vinyl ester, glycidyl, glycidyl ether, vinyl glycidyl ether, vinyl amide, vinyl triazine, vinyl isocyanurate, acrylate, methacrylate, alkacrylate, alkyl alkacrylate, phenyl, halide, thiol, cyano, cyanate, or thiocyanate. The resin formulations may contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material.
1. A preceramic resin formulation for 3D-printing and free-radical or cationic polymerization, said preceramic resin formulation comprising:
(a) a functionalized carbosilane having the chemical structure:
wherein:
R 1 is selected from the group consisting of an allyl group, an ethynyl group a vinyl ether group, a glycidyl group, a glycidyl ether group, a vinyl glycidyl ether group, a vinyl amide group, a vinyl triazine group, a vinyl isocyanurate group, a cyano group, a cyanate group, a thiocyanate group, and combinations thereof;
R 2 is selected from the group consisting of an allyl group, an ethynyl group a vinyl ether group, a glycidyl group, a glycidyl ether group, a vinyl glycidyl ether group, a vinyl amide group, a vinyl triazine group, a vinyl isocyanurate group, a cyano group, a cyanate group, and combinations thereof; and
n=2 to 100;
(b) a photoinitiator;
(c) a free-radical inhibitor; and
(d) a 3D-printing resolution agent, wherein said 3D-printing resolution agent is selected for its capability to improve 3D-print quality and resolution by containing curing to a desired region of light exposure laterally and/or vertically in a pre-cured print bath via absorbing said light at a first wavelength and converting energy produced therefrom into thermal energy or radiation at a higher wavelength.
2. The preceramic resin formulation of claim 1 , wherein at least one of R 1 or R 2 is an allyl group.
3. The preceramic resin formulation of claim 1 , wherein said preceramic resin formulation contains at least two distinct functionalized carbosilanes that are each in accordance with said chemical structure, wherein R 1 , R 2 , and n are independently selected for said distinct functionalized carbosilanes.
4. The preceramic resin formulation of claim 1 , wherein said photoinitiator is present in a concentration from about 0.001 wt % to about 10 wt % in said preceramic monomer formulation.
5. The preceramic resin formulation of claim 1 , wherein said free-radical inhibitor is present in a concentration from about 0.001 wt % to about 10 wt % in said preceramic monomer formulation.
6. The preceramic resin formulation of claim 1 , wherein said 3D-printing resolution agent is present in a concentration from about 0.001 wt % to about 10 wt % in said preceramic resin formulation.
7. The preceramic resin formulation of claim 1 , wherein said preceramic monomer formulation further comprises a thermal free-radical initiator.
8. The preceramic resin formulation of claim 1 , wherein said preceramic resin formulation further contains a crosslinking agent.
9. The preceramic resin formulation of claim 1 , wherein said preceramic monomer formulation further comprises from about 0.1 vol % to about 70 vol % of solid-phase fillers.
10. The preceramic resin formulation of claim 1 , wherein said 3D-printing resolution agent is selected from the group consisting of 2-hydroxyphenyl-benzophenones, 2-hydroxyphenyl-s-triazines, 2,2′-(2,5-thiophenediyl)bis(5-tert-butylbenzoxazole), 2,2′-(1,2-ethenediyl)bis(4,1-phenylene)bisbenzoxazole, and combinations thereof.