Actinic and thermal cure fluoropolymers with controlled porosity

Patent metadata

Field	Value
Publication number	US-2022064427-A1
Application number	US-202017006462-A
Country	US
Kind code	A1
Filing date	Aug 28, 2020
Priority date	Aug 28, 2020
Publication date	Mar 3, 2022
Grant date	—

Abstract

According to one embodiment, a mixture includes a fluoropolymer monomer having at least one functional group amenable to polymerization, a pore-forming material, and a polymerization initiator. According to another embodiment, a product includes a porous three-dimensional structure comprising a crosslinked fluoropolymer, where at least 20% of a volume measured within an outer periphery of the porous three-dimensional structure corresponds to the pores.

First claim

What is claimed is:

1 . A mixture, comprising:
a fluoropolymer monomer having at least one functional group amenable to polymerization; a pore-forming material; and a polymerization initiator.

2 . The mixture as recited in claim 1 , wherein the fluoropolymer monomer has an average atomic weight percentage of fluorine in a range of 10% to 90%.

3 . The mixture as recited in claim 1 , wherein the mixture is a liquid.

4 . The mixture as recited in claim 1 , wherein the pore-forming material is a porogen.

5 . The mixture as recited in claim 4 , wherein the porogen is a non-reactive component.

6 . The mixture as recited in claim 4 , wherein the porogen is a liquid solvent.

7 . The mixture as recited in claim 4 , wherein the porogen is a solid component.

8 . The mixture as recited in claim 4 wherein the porogen is a gaseous component.

9 . The mixture as recited in claim 1 , wherein the pore-forming material is a pore-forming substance that assists in generating gaseous species during curing.

10 . The mixture as recited in claim 1 , wherein the mixture has a viscosity in a range of 0 cP to about 100,000 cP.

11 . The mixture as recited in claim 1 , comprising less than 5 wt % of an additive selected from the group consisting of: nanoparticles, a catalyst, and an electron conductor.

12 . The mixture as recited in claim 1 , wherein the fluoropolymer monomer has at least one functional group thereon.

13 . The mixture as recited in claim 1 , wherein a concentration of the pore-forming material in the mixture is in a range of greater than 0 wt % to about 98 wt % of total mixture.

14 . The mixture as recited in claim 1 , wherein the polymerization initiator is a photoinitiator.

15 . The mixture as recited in claim 1 , wherein the polymerization initiator is a thermal initiator.

16 . A method of forming a porous three-dimensional structure, the method comprising:
forming a three-dimensional structure by an additive manufacturing technique using the mixture as recited in claim 1 ; and curing the formed three-dimensional structure.

17 . The method of claim 16 , wherein the additive manufacturing technique is selected from the group consisting of: direct laser writing via two photon polymerization, projection micro-stereolithography, and direct ink writing.

18 . The method of claim 16 , further comprising removing the pore-forming material from the cured three-dimensional structure.

19 . A method of forming a porous three-dimensional structure, the method comprising:
placing the mixture as recited in claim 1 in a shaping object selected from the group consisting of a cast and a mold; and curing the mixture in the shaping object.

20 . The method of claim 19 , further comprising removing the pore-forming material from the cured mixture.

21 . A method of forming a porous three-dimensional structure, the method comprising:
coating a substrate with the mixture as recited in claim 1 ; and curing the mixture.

22 . A product, comprising:
a porous three-dimensional structure comprising a crosslinked fluoropolymer, wherein at least 20% of a volume measured within an outer periphery of the porous three-dimensional structure corresponds to the pores.

23 . The product of claim 22 , wherein at least 50 % of the volume measured according to outer dimensions of the porous three-dimensional structure corresponds to the pores.

24 . The product of claim 22 , wherein the product is characterized by allowing passage of gasses therethrough and repelling at least liquid water.

25 . The product of claim 22 , wherein the fluoropolymer has functional groups along a backbone thereof.

Assignees

• L Livermore Nat Security Llc

Inventors

• Oakdale James
• Baker Sarah E
• Dudukovic Nikola
• Duoss Eric B
• Jue Melinda Lia Wah

Classifications

• B29K2027/12

  containing fluorine · CPC title

• B29C33/405

  Elastomers, e.g. rubber (B29C33/50 takes precedence) · CPC title

• B29C33/424

  Moulding surfaces provided with means for marking or patterning (for injection moulding B29C45/372) · CPC title

• B29C39/26

  Moulds or cores · CPC title

• B29C39/003

  characterised by the choice of material · CPC title