Methods of manufacturing poly(hexahydrotriazine)s via suspension or emulsion polymerization
View Patent ↗A method of manufacturing a hemiaminal dynamic covalent network (HDCN) comprises reacting a diamine and formaldehyde in the presence of a reaction medium comprising a polar solvent and a nonpolar solvent at a temperature of about 15° C. to about 100° C. to form the HDCN. A composition comprising the produced HDCN can be molded to form various articles comprising poly(hexahydrotriazine)s.
1. A method of manufacturing a hemiaminal dynamic covalent network, the method comprising:
reacting a diamine and formaldehyde in the presence of a reaction medium comprising a first solvent and an immiscible second solvent at a temperature of about 15° C. to about 100° C. to form the hemiaminal dynamic covalent network, wherein the reaction is conducted in an emulsion or a suspension.
2. The method of claim 1 , wherein the first solvent is a polar solvent comprising one or more of the following: 1-methyl-2-pyrrolidone; N,N-dimethyl formamide; N,N-dimethyl acetamide; dimethyl sulfoxide; hexamethylphosphoramide; diphenyl sulfone; or tetramethylene sulfone.
3. The method of claim 1 , wherein the immiscible second solvent is a nonpolar solvent comprising one or more of the following: benzene; toluene; xylenes; diethyl benzene; C5-C20 alkanes; or diethyl ether.
4. The method of claim 3 , wherein the immiscible second solvent is a paraffinic hydrocarbon.
5. The method of claim 1 , wherein the volume ratio of the first solvent relative to the immiscible second solvent is about 1:1 to about 1:5.
6. The method of claim 1 , wherein the reaction medium further comprises water.
7. The method of claim 1 , wherein the reaction medium further comprises one or more of a surfactant; or a stabilizer.
8. The method of claim 7 , wherein the surfactant comprises sorbitan esters.
9. The method of claim 7 , wherein the stabilizer comprises amphiphilic copolymers.
10. The method of claim 1 , wherein the diamine is 4,4′-oxydianiline, 4,4′-diaminodiphenylmethane, 3,3′-methylenedianiline, or 4-aminophenyl sulfone.
11. The method of claim 1 , further comprising obtaining a powder of the hemiaminal dynamic covalent network by spray drying.
12. The method of claim 1 , further comprising contacting a reaction product comprising the hemiaminal dynamic covalent network, the first solvent, and the second solvent with a polar protic solvent to precipitate the hemiaminal dynamic covalent network; and filtering the precipitated hemiaminal dynamic covalent network.
13. The method of claim 11 , further comprising drying the filtered hemiaminal.
14. A method of manufacturing a hemiaminal dynamic covalent network, the method comprising:
combining a polar phase with a nonpolar phase; the polar phase comprising a diamine, formaldehyde, and a polar solvent; and the nonpolar phase comprising a nonpolar solvent to form an emulsion or a suspension; and
reacting the diamine with formaldehyde in the emulsion or suspension to form the hemiaminal dynamic covalent network.
15. The method of claim 13 , wherein the polar phase further comprises water.
16. The method of claim 13 , wherein the nonpolar phase further comprises one or more of a surfactant or a stabilizer.
17. The method of claim 13 , wherein the volume ratio of the polar phase relative to the nonpolar phase is about 1:1 to about 1:5.
18. A method of manufacturing an article comprising a poly(hexahydrotriazine), the method comprising:
providing a composition comprising a hemiaminal dynamic covalent network manufactured according to the method of claim 1 , and
molding the composition to form an article comprising a poly(hexahydrotriazine).
19. A method of manufacturing an article comprising a poly(hexahydrotriazine), the method comprising:
providing a composition comprising a hemiaminal dynamic covalent network manufactured according to the method of claim 14 , and
molding the composition to form an article comprising a poly(hexahydrotriazine).