Polymeric energy storage materials
Compositions, coatings, and energy storage fabrications made of support polymers or active waxes in a grafted matrix to an amorphous wax and at least one functional compound and their methods of preparation are presented. Amorphous waxes are typified by paraffin waxes. Functional compounds include various fatty alcohols, fatty acids, ester, amines, and amidoalkylamines. Sulfonated and oxidized ion exchange resins may be grafted to the matrix. The compositions are capable of storing or releasing energy upon a physical phase change transition.
1. A modified wax composition capable of storing or releasing energy upon a physical phase change transition, comprising:
at least one support polymer;
at least one amorphous wax; and
at least one functional compound having a phase change active group, wherein the at least one functional compound is selected from the group consisting of fatty alcohol, unsaturated fatty alcohol, fatty acid, alkyl fatty ester, alkyl unsaturated fatty ester, fatty amine, unsaturated fatty amine, fatty amidoalkylamine, unsaturated fatty amidoalkylamine and combinations thereof,
wherein about 1% to about 70% by weight of the at least one amorphous wax is covalently bonded to the at least one support polymer, the at least one functional compound and any combination thereof, and about 1% to about 70% by weight of the at least one functional compound is covalently bonded to the at least one support polymer, the at least one amorphous wax and any combination thereof.
2. The composition of claim 1 , wherein the physical phase change transition occurs at a temperature of about 20° C. to about 60° C.
3. The composition of claim 1 , wherein the at least one functional compound is (C 10 -C 27 )alkyl-CO 2 R, (C 10 -C 27 )alkenyl-CO 2 R, (C 10 -C 26 )alkyl(COOR)(COOR′), (C 10 -C 26 )alkenyl(COOR)(COOR′), and R and R′ are independently (C 1 -C 28 )alkyl, or a glyceride.
4. The composition of claim 1 , wherein the at least one functional compound is (C 10 )alkyl(COOR)(COOR′), (C 10 )alkenyl(COOR)(COOR′), or combinations thereof; and R and R′ are independently (C 10 -C 28 )alkyl.
5. The composition of claim 1 , wherein the at least one functional compound is (C 10 -C 27 )alkyl-CO 2 R, (C 10 -C 27 )alkenyl-CO 2 R, (C 10 -C 26 )alkyl(COOR)(COOR′), (C 10 -C 26 )alkenyl(CO 2 R)(COOR′), or combinations thereof; and R and R′ are independently (C 1 -C 28 )alkyl.
6. The composition of claim 1 , wherein the at least one functional compound is (C 10 -C 27 )alkyl-CONHR, (C 10 -C 27 )alkenyl-CONHR, (C 10 -C 26 )alkyl(CONHR) (CONHR′), (C 10 -C 26 )alkenyl(CONHR′) (CONHR′), (C 10 -C 26 )alkyl(CONHR)(CO 2 H), (C 10 -C 26 )alkenyl(CONHR)CO 2 H, or combinations thereof;
R and R′ are independently —(CH 2 CH 2 Y) x —CH 2 CH 2 NH 2 ;
Y is NH, O, or S; and
x is 0, 1, 2, 3, or 4.
7. The composition of claim 1 , wherein the at least one functional compound is (C 10 -C 28 )alkyl-NR 1 R 2 R 3 , and R 1 , R 2 , and R 3 are independently hydrogen or —(C 1 -C 28 )alkyl.
8. The composition of claim 1 , further comprising at least one oxidized ion exchange resin grafted to the modified wax, wherein the at least one oxidized ion exchange resin is an oxidized strong acidic ion exchange resin, oxidized weak acidic ion exchange resin, oxidized weak basic ion exchange resin, or combinations thereof, wherein about 1% to about 70% by weight of the at least one oxidized ion exchange resin is covalently bonded therein.
9. The composition of claim 1 , wherein the at least one amorphous wax is bayberry wax, beeswax, candelilla wax, carnauba wax, castor wax, ceresin waxes, douglas-fir bark wax, Fischer-Tropsch wax, japan wax, jojoba wax, lanolin, microcrystalline wax, montan wax, ouricury wax, ozokerite wax, paraffin wax, peat wax, petroleum wax, polyethylene wax, rice bran wax, spermaceti wax, chemically modified hydrocarbon wax, substituted amide wax, or combinations thereof.
10. The composition of claim 1 , wherein the at least one amorphous wax is a paraffin wax.
11. The composition of claim 1 , wherein the at least one support polymer is a polyolefin, a vinyl polymer, or combinations thereof.
12. The composition of claim 1 , wherein the at least one support polymer is polyethylene, recycled polyethylene, waste polyethylene, or combinations thereof.
13. The composition of claim 1 , wherein the at least one support polymer is polyethylene, and the at least one support polymer is present in the composition at a concentration of about 0.5 weight % to about 10 weight %.
14. The composition of claim 1 , further comprising water.
15. The composition of claim 1 , wherein the composition has a transition enthalpy of about 150 kJ/kg to about 250 kJ/kg as determined by differential scanning calorimetry.