Monomer formulations and methods for 3D printing of preceramic polymers

A preceramic monomer formulation for 3D-printing and free-radical polymerization, said monomer formulation comprising:

• (a) from 3 wt % to 97 wt % of a monomer molecule containing (i) non-carbon atoms and (ii) two or more C═X double bonds, two or more C≡X triple bonds, or at least one C═X double bond and at least one C≡X triple bond, wherein X is selected from C, S, N, O, or a combination thereof, wherein said monomer molecule includes two or more functional groups selected from the group consisting of vinyl ether, vinyl ester, vinyl amide, vinyl triazine, vinyl isocyanurate, acrylate, methacrylate, and combinations thereof, wherein said monomer molecule does not include a functional group consisting of a pure vinyl group, wherein said pure vinyl group is not part of a vinyl ether group, a vinyl ester group, a vinyl amide group, a vinyl triazine group, or a vinyl isocyanurate group, and wherein said two or more functional groups are selected for free-radical polymerization;
• (b) a photoinitiator that generates free radicals by intramolecular bond cleavage or intermolecular hydrogen abstraction when exposed to light having a wavelength from about 200 nm to about 500 nm, wherein said photoinitiator is selected for free-radical polymerization, and wherein said photoinitiator is present in a concentration from about 0.001 wt % to about 10 wt % in said formulation;
• (c) a free-radical inhibitor that inhibits free-radical polymerization, wherein said free-radical inhibitor is present in a concentration from about 0.001 wt % to about 10 wt % in said formulation;
• (d) a thermal free-radical initiator, wherein said thermal free-radical initiator is present in a concentration from about 0.001 wt % to about 10 wt % in said formulation;
• and
• (e) a 3D-printing resolution agent selected from the group consisting of UV absorbers, fluorescent molecules, optical brighteners, and combinations thereof, wherein said 3D-printing resolution agent is present in a concentration from about 0.001 wt % to about 10 wt % in said formulation,
• wherein said preceramic monomer formulation does not include a functional group consisting of a thiol group.