Green fabrication of polytetrafluoroethylene and expanded polytetrafluoroethylene and uses thereof

Patent metadata

Field	Value
Publication number	US-11780982-B2
Application number	US-202217728188-A
Country	US
Kind code	B2
Filing date	Apr 25, 2022
Priority date	Jan 22, 2019
Publication date	Oct 10, 2023
Grant date	Oct 10, 2023

Abstract

Green, fast and easy evaporating organic solvent for use as a lubricant in the processing of polytetrafluoroethylene (PTFE) and expanded polytetrafluoroethylene (ePTFE) products and processes of using the solvents to fabricate the products are disclosed herein. The products can be used in the field of bio- and medical applications, such as for use in vascular grafts, cardiovascular and soft tissue patches, facial implants, surgical sutures, and endovascular prosthesis, and for any products known in the aerospace, electronics, fabrics, filtration, industrial and sealant arts.

First claim

What is claimed is:

1. A method of preparing an extruded product, the method comprising:
dissolving a target additive into an organic solvent to form a target-solvent solution;
immersing a polytetrafluoroethylene (PTFE) powder in the target-solvent solution to form a blend, wherein the organic solvent is present in the blend in an amount of from about 10% by weight to about 30% by weight;
preforming the blend;
extruding the preformed blend to form a product; and
evaporating the target-solvent solution from the extruded product.

2. The process as set forth in claim 1 , wherein the organic solvent is selected from the group consisting of a lower alkyl alcohols, acetic acid, ethyl acetate, acetonitrile, chloroform, benzene, methylbenzene, dimethylbenzene, acetone, 2-butanone, cyclopentanone, pentane, n-hexane, cyclohexane, heptane, dichloromethane, dichloroethane, trichloroethane, tetrachloromethane, tetrachloroethane, trimethylpentane, 1,4-dioxane, chloroform, ether, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), tetrahydrofuran (THF), and combinations thereof.

3. The process as set forth in claim 1 , wherein the organic solvent is further mixed with a carrier before blended with the PTFE powder.

4. The process as set forth in claim 1 , wherein blending comprising rolling the PTFE powder and organic solvent for a period of from about 30 minutes to about 120 minutes.

5. The process as set forth in claim 4 further comprising aging the blend for a period of from about 30 minutes to about 48 hours after rolling.

6. The process as set forth in claim 1 comprising preforming the blend at a pressure of from about 1 MPa to about 30 MPa.

7. The process as set forth in claim 1 , wherein evaporating of the organic solvent comprises heating the extruded product to a temperature of from 60° C. to about 200° C. for a period of from about 0.5 minutes to about 120 minutes.

8. The process as set forth in claim 1 further comprising expanding the extruded product.

9. The process as set forth in claim 1 , wherein the target additive is selected from the group consisting of a biofunctional material, a therapeutic, a natural compound, an aesthetic agent and combinations thereof.

10. The process as set forth in claim 9 , wherein the biofunctional material is a growth factor selected from the group consisting of epidermal growth factor (EGF), fibroblast growth factor (FGF), nerve growth factor (NGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), granulocyte-macrophage colony-stimulating factor (GMCSF), granulocyte-colony stimulating factor (GCSF), transforming growth factor (TGF), Erythropieitn, thyroperoxidase (TPO), bone morphogenetic proteins (BMP), hepatocyte growth factor (HGF), growth differentiation factors (GDF), Neurotrophins, melanocyte-specific factor (MSF), sarcoma growth factor (SGF), and combinations thereof.

11. The process as set forth in claim 1 , wherein the target additive is present in the organic solvent in an amount of from about 0.1% by weight to about 5% by weight.

12. A method for preparing an extruded product, the method comprising:
dissolving a target additive into an organic solvent to form a target-solvent solution, wherein the target additive is present in the target-solvent solution in an amount of from about 0.1% by weight to about 5% by weight;
immersing a sintered extruded polytetrafluoroethylene (PTFE) product in the target-solvent solution to form a wetted PTFE product; and
evaporating the target-solvent solution from the extruded product.

13. The process as set forth in claim 12 , wherein evaporating of the target-solvent solution comprises heating the extruded product to a temperature of from 60° C. to about 200° C. for a period of from about 0.5 minutes to about 120 minutes.

14. The process as set forth in claim 12 , wherein the target additive is selected from the group consisting of a biofunctional material, a therapeutic, a natural compound, an aesthetic agent and combinations thereof.

15. The process as set forth in claim 14 , wherein the biofunctional material is a growth factor selected from the group consisting of epidermal growth factor (EGF), fibroblast growth factor (FGF), nerve growth factor (NGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), granulocyte-macrophage colony-stimulating factor (GMCSF), granulocyte-colony stimulating factor (GCSF), transforming growth factor (TGF), Erythropieitn, thyroperoxidase (TPO), bone morphogenetic proteins (BMP), hepatocyte growth factor (HGF), growth differentiation factors (GDF), Neurotrophins, melanocyte-specific factor (MSF), sarcoma growth factor (SGF), and combinations thereof.

Assignees

• Wisconsin Alumni Res Found

Inventors

• Turng Lih-Sheng
• Xu Yiyang
• Lin Yu-Jyun
• Wang dong-fang

Classifications

• C08J9/286 Primary

  the liquid phase being a solvent for the monomers but not for the resulting macromolecular composition, i.e. macroporous or macroreticular polymers · CPC title

• A61L27/16

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• A61L27/56

  Porous materials, {e.g. foams or sponges} · CPC title

• C08J3/092

  Hydrocarbons · CPC title

• C08J2201/03

  Extrusion of the foamable blend · CPC title