3D printing of thermoset polymers and composites
The present disclosure provides a novel method of 3D printing using frontal polymerization chemistry. This method enables the printing of tough, high quality thermosets in a short time with the option of adding fiber reinforcement. As such, it facilitates fabrication of mechanically robust 3D-printed devices and structures.
1. A method for fabricating a printed thermoset polymer comprising:
a) extruding a thermoset gel from a dispensing apparatus to provide an extruded thermoset gel, the thermoset gel having a storage modulus of about 10 Pascals to about 10,000 Pascals and comprising a mixture of an organic phosphite, a ruthenium(II) catalyst, a dicyclopentadiene, and an organic solvent; and
b) triggering a frontal polymerization of the extruded thermoset gel, wherein the frontal polymerization propagates and cures the extruded thermoset gel;
wherein a printed thermoset polymer is printed by steps comprising steps a) and b).
2. The method of claim 1 wherein the thermoset gel is cooled below 25° C.
3. The method of claim 1 wherein the dispensing apparatus is cooled below 25° C.
4. The method of claim 1 wherein the extruded thermoset gel is extruded onto a platform that can trigger frontal polymerization.
5. The method of claim 4 wherein the platform is heated.
6. The method of claim 1 wherein the frontal polymerization propagates and cures the extruded thermoset gel instantly to about 60 minutes after the thermoset gel is extruded.
7. The method of claim 6 wherein the frontal polymerization is delayed by a sufficient amount of time to allow a second layer of the extruded thermoset gel to coalesce with a first layer of the extruded thermoset gel.
8. A method for polymerizing a thermoset gel comprising:
a) extruding a thermoset gel onto a platform from a cooled dispensing apparatus to provide an extruded thermoset gel; and
b) heating the platform to trigger a frontal polymerization of the extruded thermoset gel, wherein the frontal polymerization propagates and cures the extruded thermoset gel;
wherein the thermoset gel comprises triethyl phosphite, dichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene](benzylidene)(tricyclohexylphosphine)ruthenium(II), and a dicyclopentadiene;
wherein the thermoset gel is thereby polymerized.
9. The method of claim 8 wherein the thermoset gel comprises an additive to lower the melting point of the dicyclopentadiene.
10. The method of claim 9 wherein the additive is a norbornene.
11. The method of claim 8 wherein the thermoset gel has a storage modulus of about 50 Pascals to about 5,000 Pascals.
12. The method of claim 8 wherein the extruded thermoset gel is a carbon fiber composite.
13. The method of claim 1 wherein the frontal polymerization is triggered by electromagnetic irradiation.
14. The method of claim 13 , wherein the electromagnetic irradiation comprises ultraviolet light.