Bulk transient materials made of cyclic poly(phthalaldehyde)

Patent metadata

Field	Value
Publication number	US-11111378-B2
Application number	US-201916383316-A
Country	US
Kind code	B2
Filing date	Apr 12, 2019
Priority date	Apr 16, 2018
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

The present disclosure provides a composition of matter comprising purified cyclic poly(phthalaldehyde) (cPPA) and a plasticizer. The composition enables thermal processing and molding in bulk quantities, and is designed to degrade when contacted by an acid or exposed to a high enough temperature. Photodegradable cPPA containing a photooxidant is disclosed. Methods of making and recycling the composition of matter are also provided.

First claim

The invention claimed is:

1. A composition, comprising:
cyclic poly(phthalaldehyde) (cPPA);
a Lewis acid catalyst in an amount of less than about 10 μmol/g; and
a plasticizer.

2. The composition of claim 1 , wherein the Lewis acid catalyst is titanium tetrachloride, boron trifluoride, tin(IV) chloride, aluminum chloride, zinc chloride, an alkyl aluminum. chloride, or any combination thereof.

3. The composition of claim 1 , wherein the plasticizer is selected from the group consisting of: dimethylphthalate, diethylphthalate, dibutylphthalate, dihexylphthalate, dioctylphthalate, an arene, a long-chain alkyl ether, and any combination thereof.

4. The composition of claim 1 , further comprising a stabilizer comprising at least one of an arene, a long-chain alkyl ether, a sacrificial reductant, an organic base, a nucleophile, pyridine, an alkylamine, or an alcohol.

5. The composition of claim 1 , further comprising a stabilizer selected from one or more of anisole; 1,4-dimethoxybenzene; 1,3,5-trimethoxybenzene, 1,2,4-trimethoxybenzene; diphenyl ether; biphenyl, aniline; or any other organic compound with an oxidation potential lower than that of cPPA.

6. The composition of claim 1 , further comprising a stabilizer selected from the group consisting of: (2,2,6,6 tetramethylpiperidin-1-yl)oxyl (TEMPO), N,N′-di-sec -butyl-1,4 -phenylenediamine (DBPDA), and any combination thereof.

7. The composition of claim 1 , wherein the cPPA degrades when contacted by an acid or exposed to a temperature of about 120 to about 200° C.

8. The composition of claim 7 , wherein the acid comprises a strong mineral or an organic acid.

9. The composition of claim 7 , wherein the acid comprises one or more of hydrochloric acid, sulfuric acid, acetic acid, or trifluoroacetic acid.

10. A bulk transient material, comprising the composition of claim 1 and a photooxidant.

11. A device made at least in part from the composition of claim 1 .

12. A method for stabilizing cyclic poly(phthalaldehyde) (cPPA) to enable thermal processing of a bulk solid, the method comprising:
purifying cPPA by lowering a concentration of a Lewis acid catalyst to less than about 10 μmol/g; and
adding a plasticizer to the cPPA.

13. The method of claim 12 , wherein the purifying of cPPA comprises dropwise precipitation of the cPPA into a solvent, resulting in a purified cPPA having a concentration of the Lewis acid catalyst of less than about 10 μmol/g.

14. The method of claim 12 , further comprising adding a stabilizer to the cPPA.

15. A method of manufacturing a bulk transient material capable of triggered depolymerization, the method comprising:
purifying cyclic poly(phthalaldehyde) (cPPA) by lowering a concentration of a Lewis acid catalyst to less than about 10 μmol/g;
dissolving the purified cPPA in a first portion of a solvent to form a purified cPPA solution;
dissolving a plasticizer in a second portion of the solvent to form a plasticizer solution;
mixing the purified cPPA solution with the plasticizer solution to form a mixture;
casting the mixture into a film to obtain a cPPA film;
drying the cPPA film;
melting the dried cPPA film;
adding the melted cPPA into a mold;
cooling the melted cPPA to solidify the cPPA; and
removing the solidified cPPA from the mold to obtain a bulk transient material capable of triggered depolymerization.

16. The method of claim 15 , further comprising dissolving a stabilizer in the second portion of the solvent with the plasticizer.

17. The method of claim 15 , further comprising dissolving an oxidant or a photooxidant in the second portion of the solvent.

18. A method of recycling a material comprising cyclic poly(phthalaldehyde)(cPPA), comprising:
heating the material comprising cPPA to a temperature at or above a depolymerization temperature of the cPPA so as to provide degraded cPPA; and
recovering monomers from degraded cPPA.

19. The method of claim 18 . wherein the heating the material is conducted under vacuum.

20. The method of claim 18 , wherein the material further comprises a fiber.

Assignees

• Univ Illinois

Inventors

• Moore Jeffrey S
• White Scott R
• Sottos Nancy R
• Feinberg Adam M
• Plantz Christopher L
• Lopez-Hernandez Hector
• Lloyd Evan M

Classifications

• C08K5/12 Primary

  of cyclic polycarboxylic acids · CPC title

• B01J27/10

  Chlorides · CPC title

• C08K5/17

  Amines; Quaternary ammonium compounds · CPC title

• C08L2201/08

  Stabilised against heat, light or radiation or oxydation · CPC title

• C08L2203/30

  used for thermoforming · CPC title