Methods for sol-gel polymerization in absence of solvent and creation of tunable carbon structure from same
The present application is directed to methods for solvent-free preparation of polymers and their subsequent processing into activated carbon materials. These methods unexpectedly demonstrate ability to tune pore structure in the polymer gel and carbon produced there from, while also providing distinct advantages over the current art.
1. A method for preparing a polymer, comprising physically blending a mixture of particles comprising polymer precursors and aging the mixture at a temperature and for a time sufficient for the polymer precursors to react with each other and form a polymer gel, and wherein the mixture comprises less than 10% solvent by weight, and the polymer precursors are monomers.
2. The method of claim 1 , wherein the mixture comprises less than 1% solvent by weight.
3. The method of claim 1 , wherein the mixture comprises less than 0.1% solvent by weight.
4. The method of claim 1 , wherein the temperature is at or above the glass transition temperature of one or more of the polymer precursors.
5. The method of claim 1 , wherein the temperature is at or above the melting temperature of one or more of the polymer precursors.
6. The method claim 1 , wherein the temperature is 30° C. or more below the melting temperature of one or more of the polymer precursors.
7. The method of claim 1 , wherein the polymer precursors are selected from an amine-containing compound, an alcohol-containing compound and a carbonyl-containing compound.
8. The method of claim 1 , wherein the polymer precursors are selected from an alcohol, a phenol compound, a polyalcohol, a sugar, an alkyl amine, an aromatic amine, an aldehyde, a ketone, a carboxylic acid, an ester, melamine, a urea, an acid halide and an isocyanate.
9. The method of claim 8 , wherein the phenolic compound is phenol, resorcinol, naphthol, bisphenol A, or any combination thereof.
10. The method of claim 8 , wherein the sugar is fructose, sucrose, glucose, or any combination thereof.
11. The method of claim 8 , wherein the carboxylic acid is acetic acid, formic acid, oxalic acid, lactic acid, citric acid, or any combination thereof.
12. The method of claim 1 , wherein the polymer precursors comprise hexamethylenetetramine.
13. The method of claim 1 , wherein the polymer precursors comprise hexamethylenetetramine and bisphenol A.
14. The method of claim 1 , further comprising pyrolyzing the polymer gel in an inert atmosphere at temperatures ranging from 500° C. to 2400° C. to obtain pyrolyzed polymer gel particles.
15. The method of claim 14 , further comprising activating the pyrolyzed polymer gel particles to obtain activated polymer gel particles by a method comprising contacting the pyrolyzed polymer gel particles with an atmosphere comprising carbon dioxide, carbon monoxide, steam, oxygen, or combinations thereof, at a temperature may ranging from 800° C. to 1300° C.
16. A method for preparing a polymer, comprising physically blending a mixture of particles comprising polymer precursors and aging the mixture at a temperature and for a time sufficient for the polymer precursors to react with each other and form a polymer gel, and wherein the mixture comprises less than 10% solvent by weight, and the polymer precursors are monomers comprising hexamethylenetetramine and bisphenol A present at a mole ratio between 0.05:1 to 5:1, respectively.
17. The method of claim 1 , wherein the polymer precursors comprise cyanuric acid.