Additive manufactured carbon Michael addition articles and method to make them
An additive elastomeric manufactured part is comprised of extrudates comprised of a reaction product of a multifunctional Michael donor and multifunctional Michael acceptor and a rheological modifier. The additive elastomeric manufactured part may have a high elongation and resistance to heat. Said part may be made by dispensing a mixture of the multifunctional Michael donor, multifunctional Michael acceptor, rheological modifier and a catalyst through a through a nozzle to form an extrudate deposited on a base. The base, nozzle or combination thereof is moved while dispensing the mixture so that there is horizontal displacement between the base and nozzle in a predetermined pattern to form an initial layer of the material on the base. Subsequent layers are then formed on the initial layer by repeating the dispensing and movement on top of the initial layer and layers that follow.
1. A method of additive manufacturing comprising,
(i) providing a multi-functional Michael donor, rheological modifier, a multi-functional Michael acceptor, and a catalyst, wherein the multi-functional Michael donor is an ester of an alcohol and further wherein the catalyst is a tertiary amine compound, amidine compound, quaternary ammonium hydroxide, alkali metal hydroxide, alkali metal alkoxide, alkali metal acetylacetonate, quaternary ammonium acetylacetonates or mixture thereof,
(ii) mixing the multi-functional Michael donor, the rheological modifier, the multi-functional Michael acceptor, and the catalyst to form a mixture,
(iii) dispensing the mixture through a nozzle to form an extrudate deposited on a base,
(iv) moving the base, nozzle or combination thereof while dispensing the mixture so that there is horizontal displacement between the base and nozzle in a predetermined pattern to form an initial layer of the extrudate on the base, and
(v) repeating steps (ii) and (iv) to form a successive layer of the extrudate adhered on the initial layer to form an additive manufactured part.
2. The method of claim 1 , wherein the method further comprises repeating step (v) such that a plurality of successive layers are adhered and built up forming the additive manufactured part.
3. The method of claim 1 , wherein the mixture has a yield stress of at least about 20 Pa.
4. The method of claim 1 , wherein the mixture, prior to curing, has a viscosity of at least 10,000 centipoise at a shear rate of 5 s −1 and a viscosity that is at least 10 times less at a shear rate of 100 s −1 .
5. The method of claim 1 , wherein the multi-functional Michael donor, and multi-functional Michael acceptor are separately provided in two separate components with a first component being comprised of the Michael donor and the rheological modifier and the second component being comprised of the Michael acceptor and rheological modifier, wherein the catalyst is provided in either the first component, second component or both.
6. The method of claim 5 , wherein the nozzle is comprised of a mixer that is a static mixer, dynamic mixer or combination thereof in which the first and second components are mixed to form the mixture.
7. The method of claim 6 , wherein the first and second component have a yield stress of at least about 20 Pa.
8. The method of claim 5 , wherein the first and second component have a viscosity of at least 10,000 centipoise at a shear rate of 5 s −1 and a viscosity that is at least 10 times less at a shear rate of 100 s −1 .
9. The method of claim 1 , wherein the multifunctional Michael donor and the multifunctional Michael acceptor are provided at a donor/acceptor functionality molar ratio from 1/3 to 3.
10. The method of claim 9 , wherein the donor/acceptor functionality molar ratio is 3/4 to 5/4.
11. The method of claim 1 , wherein at least one of the multifunctional Michael addition donor or multifunctional Michael addition acceptor has an average functionality of 3.
12. The method of claim 1 , wherein the multi-functional Michael acceptor is an acrylate compound.
13. The method of claim 1 , wherein the extrudate has a cross-sectional shape that is a polygon.
14. The method of claim 1 , wherein the predetermined pattern is such that extrudates having voids between them are first formed followed by dispensing of extrudates that deposit in said voids to form the initial layer or subsequent layer.
15. An additive manufactured article made by the method of claim 1 .
16. The method of claim 1 , wherein the rheological modifier has an oil absorption number in cc/100 g and iodine number in mg/g when multiplied together have a product that is at least 6000.
17. An additive manufactured article comprised of extrudates adhered together in layers and between the layers, wherein the extrudates are comprised of a rheological modifier and a reaction product of a multifunctional Michael addition donor and a multifunctional Michael acceptor, wherein the multi-functional Michael donor is an ester of an alcohol.
18. The additive manufactured article of claim 17 , wherein the tensile elongation at break is at least 50%.
19. The additive manufactured article of claim 17 , wherein the additive manufactured article has a decomposition temperature of at least 250° C.
20. The additive manufactured article of claim 17 , wherein the rheological modifier has an oil absorption number in cc/100 g and iodine number in mg/g when multiplied together have a product that is at least 6000.