Organic flexible ferroelectric polymer nanocomposites

Patent metadata

Field	Value
Publication number	US-11034829-B2
Application number	US-201816609127-A
Country	US
Kind code	B2
Filing date	May 1, 2018
Priority date	Apr 28, 2017
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

The present invention discloses organic flexible ferroelectric polymer nanocomposites. The present invention discloses a composite of fluorinated polymers or their copolymers with halogenated cellulosic materials and a facile process for the conversion of non-electroactive alpha phase of fluorinated polymer to electroactive beta phase of fluorinated polymer. Further, it discloses a device comprising the composite with enhanced dielectric properties.

First claim

We claim:

1. A composite comprises:
a. 90-99.9 weight % fluorinated polymers or their copolymers; and
b. 0.1-10 weight % halogenated cellulosic materials,
wherein the polymer is poly(vinylidene fluoride) and the copolymer is poly(vinylidene fluoride-co-hexafluoropropylene), and the polymer or copolymer comprises 80-99% β phase of the poly(vinylidene fluoride) or pol(vinylidene fluoride-co-hexafluoropropylene).

2. The composite as claimed in claim 1 , wherein the halogenated cellulosic materials comprise a halogen selected from the group consisting of fluorine, chlorine, bromine, and iodine.

3. The composite as claimed in claim 1 , wherein the halogenated cellulosic materials comprise a cellulosic material selected from the group consisting of micro-fibres, nano fibres, whiskers, and crystals.

4. The composite as claimed in claim 1 , wherein the β phase of said poly(vinylidene fluoride) or poly(vinylidene fluoride-co-hexafluoropropylene) is induced by the halogenated cellulosic materials.

5. The composite as claimed in claim 1 , wherein the composite generates peak to peak open circuit voltage in the range of 5-15 V.

6. The composite as claimed in claim 1 , wherein the composite charges a 4.7 μF capacitor up to 0.7V within 15 seconds.

7. The composite as claimed in claim 1 , wherein dielectric constant, power density, breaking elongation, breaking strength of the composite is in the range of 12-32; 150-800 μW/cm 3 , 5-16%, and 25-45 MPa, respectively.

8. A process for the preparation of the composite as claimed in claim 1 , wherein the process comprises the steps of:
a. dispersing the 0.1-10 weight % halogenated cellulosic materials in a solvent to obtain a dispersion;
b. adding the 90-99.9 weight % fluorinated polymers or their copolymers to the dispersion of step a. to obtain a mixture;
c. heating the mixture as obtained in step b. at a temperature in the range of 50-100° C. with stirring for period in the range of 1-5 hours and
d. precipitating the mixture of step c. by adding methanol and drying the precipitate to obtain the composite.

9. A device comprising a composite, wherein the composite comprises:
a. 90-99.9 weight % fluorinated polymers or their copolymers; and
b. 0.1-10 weight % halogenated cellulosic materials,
wherein the polymer is poly(vinylidene fluoride) and the copolymer is poly(vinylidene fluoride-co-hexafluoropropylene), and the polymer or copolymer comprises 80-99% β phase of the poly(vinylidene fluoride) or poly(vinylidene fluoride-co-hexafluoropropylene).

Assignees

• Council Scient Ind Res

Inventors

• Shanmuganathan Kadhiravan
• Farsa Ram

Classifications

• C08J2327/20

  Homopolymers or copolymers of hexafluoropropene · CPC title

• C08J5/045

  with vegetable or animal fibrous material · CPC title

• C08J2401/08

  Cellulose derivatives · CPC title

• C08L27/16 Primary

  Homopolymers or copolymers or vinylidene fluoride · CPC title

• C08L27/20

  Homopolymers or copolymers of hexafluoropropene · CPC title