Polymers for caloric applications

Patent metadata

Field	Value
Publication number	US-2021032384-A1
Application number	US-201816755476-A
Country	US
Kind code	A1
Filing date	Oct 10, 2018
Priority date	Oct 11, 2017
Publication date	Feb 4, 2021
Grant date	—

Abstract

Various embodiments disclosed relate to unsaturated polymers that exhibit electrocaloric properties. The polymers can be useful as heat transfer materials in heating and cooling applications.

First claim

1 . A polymer having the formula:

wherein
n is an integer ranging from 1 to 1000;
m is an integer ranging from 1 to 1000;
p is an integer greater than n+m;

wherein at each occurrence R 1 , R 2 , R 3 , and R 4 are independently chosen from H, F, Cl, Br, I, —NH 2 , —NHZ, —NZ 2 , 13BH 2 , —BHZ, —BZ 2 , OZ, —SeZ, —TeZ, —SO 2 Z, —OCOZ, —NHCOZ, —COOZ, —CONH 2, —CONHZ, —CONZ 2, —CH 2 F, and —CHF 2, wherein Z is independently at each occurrence hydrogen, alkyl, aryl, or aralkyl.

2 . The polymer of claim 1 , wherein at each occurrence R 1 , R 2 , R 3 , and R 4 are independently chosen from H, F, Cl, and Br.

3 . The polymer of claim 1 , wherein at each occurrence R 1 , R 2 , R 3 , and R 4 are each independently chosen from H and F.

4 . The polymer of claim 1 , wherein the polymer is unbranchcd.

5 . The polymer of claim 1 , wherein the polymer comprises a co-polymer of at least one monomer selected from trifluoroethylene (TrFE), tetrafluoroethylene (TFE), fluoroethylene (FE), ethylene (ET), 1-chloro-1-fluoroethylen (CFE), chlorotrifluoroethylene (CTFE), chlorodifluoroethylene (CDFE), vinylidene chloride (VDC), tetrachloroethylene (TCE), tetrabromoethylene (TBE), tribromoethylene (TrBE), 1,1-dibromoethylene (DBE), bromoethylene (BE), 1,1-dibromo-2,2-difluoroethylene (DBDFE), or 1,1-dichloro-2,2-dibromoethylene (DCDBE), or combinations thereof.

6 . The polymer of claim 5 , wherein the co-polymer comprises a terpolymer.

7 . The polymer of claim 1 , wherein the polymer exhibits an adiabatic temperature change of at least 1° C. when the polymer is exposed to an electric field.

8 . The polymer of claim 1 , wherein the polymer has a number average molecular (M w ) weight of between about 5,000 g/mol and about 100,000 g/mol.

9 . The polymer of claim 5 , wherein the polymer is a co-polymer of TrFE.

10 . A method of making the polymer of claim 1 , comprising:
reacting a saturated precursor of the compound of Formula I with a base to form the polymer of Formula I.

11 . The method of claim 10 , wherein the base is an alkali metal hydroxide.

12 . The method of claim 11 , wherein the alkali metal hydroxide is NaOH.

13 . The method of claim 10 , wherein the reacting occurs in one or more organic solvents.

14 . The method of claim 13 , wherein the solvent comprises isopropanol and dimethylacetamide.

15 . The method of claim 14 , wherein the solvent has a dimethylacetamide:isopropanol v/v ratio ranging from about 5:1 to about 15:1.

16 . The method of claim 10 , wherein the reacting comprises dehydrofluorination.

17 . A method of making a polymer of claim 1 , comprising:
dehydrofluorinating polyvinylidene difluoride with NaOH in a solvent comprising a 5:1 to a 10:1 v/v ratio of dimethylacetamide:isopropanol to form the polymer of Formula I; and purifying the polymer of Formula I.

18 . An electrocaloric relaxor ferroelectric material comprising the polymer of claim 1 .

19 . An apparatus for heating or cooling comprising the polymer of claim 1 .

20 . The apparatus of claim 15 , wherein the apparatus comprises a refrigerator, air conditioner, gas liquefier, dehumidifier, heat pump, heat management device, or combinations thereof.

Assignees

• Univ Iowa State Res Found Inc

Inventors

• Balema Viktor
• Pecharsky Vitaiij
• Johnson Duane

Classifications

• C08F214/22 Primary

  Vinylidene fluoride · CPC title

• C08F8/26

  Removing halogen atoms or halogen-containing groups from the molecule · CPC title

• H01L37/025

  Electricity · mapped topic

• H10N15/15

  Thermoelectric active materials · CPC title