ABSORBENT POLYMERS, AND METHODS OF PRODUCING THEREOF AND USES THEREOF
Provided herein are absorbent polymers produced from beta-propiolactone, and methods of producing such polymers. These absorbent polymer may be cross-linked. The beta-propiolactone may be derived from ethylene oxide and carbon monoxide. The absorbent polymer may be bio-based and/or bio-degradable. The absorbent polymers may be used for diapers, adult incontinence products, and feminine hygiene products, as well as for agricultural applications.
1 . A method of producing a cross-linked polymer, comprising combining beta-propiolactone and a cross-linker in the presence of a metal cation to produce the cross-linked polymer,
wherein the cross-linked polymer comprises a partially neutralized polyacrylic acid backbone and a plurality of polypropiolactone side chains, and cross-linking moieties.
2 . The method of claim 1 , wherein the metal cation is provided as a metal salt.
3 . The method of claim 2 , wherein the metal is an alkali metal or an alkali-earth metal.
4 . The method of claim 2 , wherein the metal is sodium or potassium.
5 . The method of claim 2 , wherein the metal cation is provided as metal acrylate.
6 . The method of claim 5 , wherein the metal acrylate is sodium acrylate or potassium acrylate.
7 . A method of producing a cross-linked polymer, comprising combining beta-propiolactone and a cross-linker to produce the cross-linked polymer,
wherein the cross-linked polymer comprises a partially neutralized polyacrylic acid backbone and a plurality of polypropiolactone side chains, and cross-linking moieties.
8 . The method of claim 1 , wherein the polypropiolactone side chains independently have a structure of formula —(CH 2 CH 2 (C═O)—O) n − M + , wherein:
n is an integer from 1 to 10 inclusive; and
M + is an alkali metal, a cross-linking moiety, or H + .
9 . The method of claim 1 , wherein the cross-linker comprises:
an acrylamide compound,
a metal acrylate compound,
an organic carbonate compound,
a diglycidyl compound, or
a vinyl-organic compound comprising two or more vinyl groups,
or any combination thereof.
10 . The method of claim 1 , wherein the cross-linker comprises ethyleneglycol dimethacrylate, diethyleneglycol diacrylate, allylmethacrylate, 1,1,1-trtimethylpropane triacrylate, triallylamine, or tetraallyoxyethane, or any combination thereof.
11 . The method of claim 1 , wherein the cross-linker comprises N,N′-methylenebis(acrylamide), aluminum acrylate, ethylene carbonate, and ethylene glycol diglycidyl ether, or any combination thereof.
12 . The method of claim 1 , wherein the cross-linker comprises a silane compound.
13 . The method of claim 12 , wherein the silane compound has a structure of formula Y 3 SiR a N + R 1 R 2 R 3 X − , wherein:
Y is a hydrolyzable radical;
R a is a divalent hydrocarbon radical;
each of R 1 , R 2 and R 3 is independently:
a saturated or unsaturated hydrocarbon radical, or
a saturated or unsaturated organic radical comprising carbon, hydrogen, and at least one heteroatom selected from the group consisting of oxygen, sulfur and nitrogen; and
X − is an anion.
14 . The method of claim 13 , wherein R a is a divalent hydrocarbon radical with 1 to 6 carbon atoms.
15 . The method of claim 13 , wherein each of R 1 , R 2 and R 3 is independently a saturated or unsaturated organic radical comprising (i) carbon, hydrogen and oxygen, (ii) carbon, hydrogen, and sulfur, or (iii) carbon, hydrogen and nitrogen.
16 . The method of claim 13 , wherein each of R 1 , R 2 and R 3 is independently a saturated or unsaturated organic radical consisting of (i) carbon, hydrogen and oxygen, (ii) carbon, hydrogen, and sulfur, or (iii) or carbon, hydrogen and nitrogen.
17 . The method of claim 13 , wherein X − is chloride, bromide, fluoride, iodide, acetate or tosylate.
18 . The method of claim 1 , wherein the cross-linker comprises a polyol, a polyglycidyl ether, or a combination thereof.
19 . The method of claim 1 , wherein the cross-linker comprises a polysaccharide.
20 . The method of claim 1 , wherein the cross-linking moieties connect carboxylic end groups of at least a portion of the polypropiolactone side chains.
21 . The method of claim 1 , wherein the cross-linking moieties connect neutralized carboxylate groups of at least a portion of the polypropiolactone side chains.
22 . The method of claim 1 , wherein the cross-linking moieties connect at least a portion of the partially neutralized polyacrylic acid backbone.
23 . The method of claim 1 , further comprising combining the beta-propiolactone and the cross-linker with an ionic initiator, or a radical initiator, or a combination thereof.
24 . The method of claim 23 , wherein the ionic initiator comprises a salt of an alkali metal, a salt of an alkali-earth metal, or a combination thereof.
25 . The method of claim 23 , wherein the ionic initiator comprises a carboxylate salt of an alkali metal, a salt of an alkali-earth metal, or a combination thereof.
26 . The method of claim 23 , wherein the ionic initiator is a salt of an alkali metal.
27 . The method of claim 23 , wherein the ionic initiator has a structure of formula CH 2 ═CH 2 CO 2 − Z + , wherein Z + is an alkali metal, an alkali earth metal, ammonium, a quaternary ammonium cation, or phosphonium.
28 . The method of claim 27 , wherein the quaternary ammonium cation is a lower alkyl quaternary ammonium cation.
29 . The method of claim 23 , wherein the ionic initiator is sodium acrylate, or potassium acrylate, or a combination thereof.
30 . The method of claim 23 , wherein the ionic initiator is a methacrylate.
31 . The method of claim 23 , wherein the ionic initiator is sodium methacrylate, or potassium methacrylate, or a combination thereof.
32 . The method of claim 23 , wherein the radical initiator comprises a peroxide, a persulfate, or an azo compound, or a combination thereof.
33 . The method of claim 23 , wherein the radical initiator is a redox initiator.
34 . The method of claim 23 , wherein the radical initiator comprises a hydroperoxide.
35 . The method of claim 23 , wherein the radical initiator comprises hydrogen peroxide.
36 . The method of claim 1 , further comprising combining the beta-propiolactone and the cross-linker with an additional monomeric compound.
37 . The method of claim 36 , wherein the additional monomeric compound is an organic compound comprising at least one vinyl group.
38 . The method of claim 36 , wherein the additional monomeric compound is methacrylic acid.
39 . The method of claim 36 , wherein the additional monomeric compound is an optionally substituted acrylic acid, or a carbohydrate, or any combination thereof.
40 . The method of claim 1 , further comprising carbonylating ethylene oxide to produce the beta-propiolactone.
41 . The method of claim 1 , further comprising combining ethylene oxide and carbon monoxide in the presence of a carbonylation catalyst and optionally a solvent to produce the beta-propiolactone.
42 . A method of producing a cross-linked polymer, comprising: reacting a low molecular weight polypropiolactone with a radical polymerization initiator and a cross-linker,
wherein the low molecular weight polypropiolactone has a formula CH 2 ═CH 2 —(C═O)—O—(CH 2 CH 2 (C═O)—O) n − M + ,
wherein n is an integer from 1 to 10 inclusive; and
M + is an alkali metal, a cross-linking moiety, or H + .
43 . A polymer produced according to the method of claim 1 .
44 . A polymer comprising a poly(sodium acrylate/acrylic acid) backbone and a plurality of polypropiolactone side chains connected to the backbone.
45 . The polymer of claim 44 , wherein the polymer is cross-linked.
46 . A polymer comprising a partially neutralized polyacrylic acid backbone and a plurality of polypropiolactone side chains, and cross-linking moieties.
47 . The polymer of claim 46 , wherein the polypropiolactone side chains independently have a structure of formula —(CH 2 CH 2 (C═O)—O) n − M + , wherein:
n is an integer from 1 to 10 inclusive; and
M + is an alkali metal, a cross-linking moiety, or H + .
48 . The polymer of claim 43 , wherein the polymer has:
(i) a number average molecular weight over 1 million Dalton; or
(ii) an average particle size between 400 and 500 μm; or
(iii) a particle size distribution of more than 70% of particles between 300 μm and 600 μm; or
(iv) an extractables content less than 20%; or
(v) a residual monomer content less than 1500 ppm;
or any combination of (i) to (v).
49 . The polymer of claim 43 , wherein the polymer has:
(i) an absorbency under load between 10 g/g and 25 g/g; or
(ii) a speed of absorbance between 15 g/g and 20 g/g;
(iii) a swelling capacity between 30 g/g and 35 g/g; or
any combination of (i) to (iii).
50 . The polymer of claim 43 , wherein the polymer has:
an absorbency under load between 12 g/g and 22 g/g; and
a speed of absorbance between 15 g/g and 20 g/g.
51 . The polymer of claim 43 , wherein the polymer is bio-based as defined by ASTM D6866.
52 . The polymer of claim 51 , wherein the polymer has a bio-based content greater than 0% but less than 100%.
53 . The polymer of claim 51 , wherein the polymer has a bio-content of at least 20%.
54 . The polymer of claim 43 , wherein the polymer is biodegradable as defined by ASTM D5338-15.
55 . An absorbent article, comprising a polymer of claim 43 .
56 . The absorbent article of claim 55 , further comprising at least one inorganic or organic additive.
57 . The absorbent article of claim 55 , wherein the absorbent article is a diaper, an adult incontinence product, or a feminine hygiene product.
58 . The absorbent article of claim 55 , wherein the absorbent article is biodegradable.
59 . A biodegradable fabric, comprising:
a polymer of claim 43 ; and
at least one inorganic or organic additive.
60 . An agricultural product, comprising a polymer of claim 43 .
61 . The agricultural product of claim 60 , wherein the agricultural product is a material to hold water for crops.
62 . The agricultural product of claim 60 , wherein the agricultural product is a seed or a crop.
63 . A seed, wherein the seed is coated with a polymer of claim 43 .
64 . A seed mix, comprising a plurality of seeds, wherein at least a portion of the seeds is coated with a polymer of claim 43 .
65 . A method, comprising planting seeds of claim 63 .
66 . The method of claim 65 , further comprising growing the seeds into plants under conditions suitable for the polymer to bio-degrade to release water to the seeds, the plants, or a combination thereof.