Membranes comprising amino acid mobile carriers
In one aspect, the present invention provides a curable composition useful in the preparation of a gas separation membrane. The curable composition comprises a polyvinyl alcohol; an aliphatic polyamine; a polyglycidyl ether; and a salt of a C 2 to C 4 heterocyclic amino acid. In another aspect the present invention provides a composition comprising a crosslinked polyvinyl alcohol comprising structural units derived from a polyglycidyl ether, a polyamine and the salt of a C 2 to C 4 heterocyclic amino acid. The compositions are useful in the preparation of gas separation membranes in which the C 2 to C 4 heterocyclic amino acid in the form of its salt functions as a mobile carrier of carbon dioxide.
1. A curable composition comprising:
a polyvinyl alcohol;
an aliphatic polyamine;
a polyglycidyl ether; and
a salt of a C 2 to C 4 heterocyclic amino acid.
2. The composition according to claim 1 , wherein the aliphatic polyamine is at least one selected from the group consisting of polyallylamine, polyvinylamine, polydiallylamine, poly(vinylamine-co-vinylalcohol), polyethyleneimine, and poly(ethyleneimine-co-ethylene oxide).
3. The composition according to claim 1 , wherein the polyamine is polyallylamine.
4. The composition according to claim 1 , wherein the polyglycidyl ether is at least one selected from the group consisting of glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolpropane diglycidyl ether, ethylene glycol diglycidyl ether, bisphenol-A diglycidyl ether, diethylene glycol diglycildyl ether, triethylene glycol diglycidyl ether, and propane diol diglycidyl ether.
5. The composition according to claim 1 , wherein the polyglycidyl ether is ethylene glycol diglycidyl ether.
6. The composition according to claim 1 , wherein the salt of a heterocyclic amino acid comprises at least one metal cation is selected from the group consisting of lithium, sodium, potassium, calcium, and magnesium.
7. The composition according to claim 1 , wherein the salt of a heterocyclic amino acid comprises potassium.
8. The composition according to claim 1 , wherein the salt of a heterocyclic amino acid is a salt of proline.
9. The composition according to claim 1 , which is free of formaldehyde or formaldehyde equivalents.
10. The composition according to claim 1 , comprising:
from about 10 weight percent to about 70 weight percent of the polyvinyl alcohol based on a total weight of the composition;
from about 1 weight percent to about 50 weight percent of the polyamine based on a total weight of the composition;
from about 5 weight percent to about 40 weight percent of the polyglycidyl ether based on a total weight of the composition; and
from about 10 weight percent to about 50 weight percent of the salt of a heterocyclic amino acid based on a total weight of the composition.
11. The composition according to claim 1 , comprising:
from about 35 weight percent to about 50 weight percent of the polyvinyl alcohol based on a total weight of the composition;
from about 5 weight percent to about 20 weight percent of the polyamine based on a total weight of the composition;
from about 10 weight percent to about 20 weight percent of the polyglycidyl ether based on a total weight of the composition; and
from about 15 weight percent to about 30 weight percent of the salt of a heterocyclic amino acid based on a total weight of the composition.
12. An article comprising the composition of claim 1 .
13. A gas separation membrane precursor comprising the composition of claim 1 disposed as a film upon a porous support.
14. A curable composition comprising:
a polyvinyl alcohol;
a polyallylamine;
ethylene glycol diglycidyl ether; and
a salt of proline.
15. The composition according to claim 14 , which is free of formaldehyde or formaldehyde equivalents.
16. The composition according to claim 15 , wherein the salt of proline is present in an amount corresponding to from about 10 weight percent to about 50 weight percent based on a total weight of the composition.