Expandable Functional TFE Copolymer Fine Powder, the Expandable Functional Products Obtained Therefrom and Reaction of the Expanded Products

• US 20100248324A1
• Filed: 03/24/2009
• Published: 09/30/2010
• Est. Priority Date: 03/24/2009
• Status: Active Grant

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Chen, Xin Kang, Xu, Ping, Hegenbarth, Jack J.
• Granted Patent: US 9,139,669 B2
• Time in Patent Office: Days
• US Class Current: 435/180
• CPC Class Codes: B29C 55/005 characterised by the choice of materials
• CPC Class Codes: B29K 2027/18 PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: B29K 2105/04 cellular or porous
• CPC Class Codes: C08F 14/26 Tetrafluoroethene
• CPC Class Codes: C08F 2/22 Emulsion polymerisation
• CPC Class Codes: C08F 214/26 Tetrafluoroethene
• CPC Class Codes: C08F 214/262 with fluorinated vinyl ethers
• CPC Class Codes: C08J 2201/03 Extrusion of the foamable blend
• CPC Class Codes: C08J 2327/18 Homopolymers or copolymers of tetrafluoroethylene
• CPC Class Codes: C08J 9/141 Hydrocarbons
• CPC Class Codes: C08J 9/228 Forming foamed products
• CPC Class Codes: C08J 9/40 Impregnation
• CPC Class Codes: C08J 9/405 with polymerisable compounds

Abstract

A functional TFE copolymer fine powder is described, wherein the TFE copolymer is a polymer of TFE and at least one functional comonomer, and wherein the TFE copolymer has functional groups that are pendant to the polymer chain. The functional TFE copolymer fine powder resin is paste extrudable and expandable. Methods for making the functional TFE copolymer are also described. The expanded functional TFE copolymer material may be post-reacted after expansion.

Claims

1. A functional TFE copolymer fine powder resin comprising

a TFE copolymer comprising a polymer chain of TFE and at least one comonomer having a functional group pendant to the polymer chain,

wherein the functional TFE copolymer fine powder resin is paste extrudable and expandable into a porous functional TFE copolymeric material having a microstructure characterized by nodes interconnected by fibrils.

2. The functional TFE copolymer fine powder resin of claim 1, wherein the at least one comonomer is a fluorinated monomer.

3. The functional TFE copolymer fine powder resin of claim 1, wherein the at least one comonomer is a perfluorinated monomer.

4. The functional TFE copolymer fine powder resin of claim 1, wherein the at least one comonomer having a functional group is between 0.01 and 5 mol % of the total polymer.

5. The functional TFE copolymer fine powder resin of claim 1, wherein the at least one comonomer having a functional group is between 0.01 and 3 mol % of the total polymer.

6. The functional TFE copolymer fine powder resin of claim 1, wherein the at least one comonomer having a functional group is between 0.01 and 2 mol % of the total polymer.

7. The functional TFE copolymer fine powder resin of claim 1, wherein the at least one comonomer having a functional group is a fluorovinyl ether of the general formula CF₂═

CF—

OR_fZ, where R_f represents a fluoro alkyl group optionally interrupted by one or more oxygen(s) and Z represents a functional group.

8. The functional TFE copolymer fine powder resin of claim 7, wherein Z is, nitrile, aldehyde, carboxylic acid or salt, ester, amine, amide, carbonyl halide, sulfonyl halide, sulfonic acid or salts thereof, sulfonamide, sulfonimide, anhydride, sulfide, phosphonic acid or salts thereof, hydroxy (alcohol) sulfate esters, phosphate esters, or isocynate.

9. The functional TFE copolymer fine powder resin of claim 7, wherein the at least one comonomer comprising a functional group comprises a fluorovinyl ether selected from ester vinyl ether, sulfonyl fluoride vinyl ether or cyano vinyl ether.

10. The functional TFE copolymer fine powder resin of claim 1, wherein the at least one comonomer comprising a functional group is selected from perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene) (8 CNVE), perfluoro(8-carboxymethyl-5-methyl-3,6-dioxa-1-octene) (EVE), or perfluoro(8-sulfonic acid fluoride-5-methyl-3,6-dioxa-1-octene) (PSVE).

11. The functional TFE copolymer fine powder resin of claim 1, further comprising a first comonomer comprising a first functional group and a second comonomer comprising a second functional group.

12. The functional TFE copolymer of claim 11, wherein the second functional group is different from the first functional group.

13. The functional TFE copolymer of claim 11, wherein the second functional group is the same as the first functional group.

14. The functional TFE copolymer fine powder resin of claim 1, further comprising at least one additional comonomer without a pendant functional group.

15. A functional TFE copolymer dispersion comprising

a fluorosurfactant,

water, and

polymerized particles of a functional TFE copolymer having a polymer chain of TFE and at least one comonomer having a functional group that is pendant to the polymer chain,

wherein the dispersion can be processed to form a fine powder resin that is paste extrudable and expandable into a porous polymeric material having a microstructure characterized by nodes interconnected by fibrils.

16. A process for making an expandable functional TFE copolymer fine powder comprising:

a) emulsifying at least one comonomer having a functional group to form an emulsion comprising the functional comonomer, water and a fluorosurfactant;

b) providing at least a portion of the emulsion to the polymerization vessel;

c) providing TFE to the polymerization vessel; and

d) polymerizing TFE and the at least one functional comonomer in an aqueous dispersion polymerization process

e) essentially completely consuming in the polymerization the at least one or removing the at least one comonomer from the polymerization vessel prior to completion of the polymerization;

f) continuing the polymerization of the TFE after essentially completely consuming or removing the at least one functional comonomer to form functional TFE copolymer; and

g) collecting a dispersion of particles of a functional TFE copolymer having pendant functional groups that can be formed into a fine powder resin that is paste extrudable and expandable into a microstructure having nodes interconnected to fibrils.

17. The process of claim 16, wherein the step of essentially completely consuming in the polymerization or removing the at least one comonomer having functional groups occurs prior to 80% completion of the polymerization.

18. The process of claim 16, wherein the step of essentially completely consuming in the polymerization or removing the at least one comonomer having functional groups occurs prior to 90% completion of the polymerization.

19. The process of claim 16, wherein the at least one functional comonomer is added prior to the initiation of polymerization.

20. The process of claim 16, further comprising adding at least one non-functional comonomer to the polymerization process.

21. The process of claim 20, wherein at least one non-functional comonomer is essentially completely consumed by polymerization or removed prior to 80% completion of the polymerization.

22. The process of claim 20, wherein at least one non-functional comonomer is essentially completely consumed by polymerization or removed prior to 90% completion of the polymerization.

23. An expanded polymeric material comprising a functional TFE copolymer material having a microstructure characterized by nodes interconnected by fibrils wherein the TFE copolymer comprises a polymer chain of TFE and at least one comonomer having a functional group that is pendant to the polymer chain.

24. The expanded polymeric material of claim 23, wherein the functional TFE copolymer comprises at least two comonomers wherein at least one comonomer does not contain a pendant functional group.

25. The expanded polymeric material of claim 23, wherein the functional TFE polymer comprises at least two comonomers each having a different functional group.

26. The expanded polymeric material of claim 23, wherein the expanded polymeric material is microporous.

27. The expanded polymeric material of claim 23, wherein the at least one comonomer having a functional group is between 0.01 mol % to 5 mol % of the total polymer.

28. The expanded polymeric material of claim 23, wherein the at least one comonomer having a functional group is between 0.01 to 3 mol % of the total polymer.

29. The expanded polymeric material of claim 23, wherein the at least one comonomer having a functional group is between 0.01 to 2 mol % of the total polymer.

30. The expanded polymeric material of claim 23, wherein the at least one comonomer having a functional group is a fluorinated monomer.

31. The expanded polymeric material of claim 23, wherein the at least one comonomer is a perfluorinated monomer.

32. The expanded polymeric material of claim 23, wherein the at least one comonomer is a fluorovinyl ether.

33. The expanded polymeric material of claim 23, wherein the at least one comonomer is a cyano vinyl ether.

34. The expanded polymeric material of claim 23, wherein the at least one comonomer is a sulfonyl fluoride vinyl ether.

35. The expanded polymeric material of claim 23, wherein the at least one comonomer is an ester vinyl ether.

36. The expanded polymeric material of claim 23, wherein the at least one comonomer is a fluorovinyl ether comonomer of the general formula CF₂═

CF—

OR_fZ, where R_f represents a fluoro alkyl group optionally interrupted by one or more oxygen(s) and Z represents a functional group.

37. The expandable polymeric material of claim 36, wherein Z is nitrile, aldehyde, carboxylic acid or salts thereof, ester, amine, amide, carbonyl halide, sulfonyl halide, sulfonic acid or salts thereof, sulfonamide, sulfonimide, anhydride, sulfide, phosphonic acid or salt, hydroxyl (alcohol) sulfate esters, phosphate esters, or isocynate.

38. The expanded polymeric material of claim 23, wherein the TFE copolymer comprises at least one functional group selected from carboxylic acid, sulfonic acid, phosphonic acid, ester, cyano, nitrile, amine, alcohol, and amidine.

39. A process for making an expanded functional TFE copolymer material comprising:

a) emulsifying at least one functional comonomer having a functional group to form a functional comonomer emulsion comprising water, and a fluorosurfactant;

b) providing at least a portion of the functional comonomer emulsion to the polymerization vessel;

c) providing TFE to a polymerization vessel;

d) polymerizing TFE and the at least one functional comonomer in an aqueous dispersion polymerization process;

e) essentially completely consuming in the polymerization or removing the at least one functional comonomer prior to completion of the polymerization;

f) continuing polymerization of the TFE after essentially completely consuming the at least one functional comonomer and collecting a dispersion of particles of a functional TFE copolymer having pendant functional groups,

g) coagulating the dispersion of particles or fine powder of the functional TFE copolymer;

h) washing and drying the coagulated particles or fine powder of the functional TFE copolymer; and

i) processing by paste extrusion and expanding into a porous polymeric material having a microstructure of nodes interconnected to fibrils.

40. The process of claim 39, wherein the polymerization of the functional comonomer is completed prior to 80% completion of the TFE polymerization.

41. The process of claim 39, wherein the polymerization of the functional comonomer is completed prior to 90% completion of the TFE polymerization.

42. The process of claim 39 further comprising adding at least one non-functional comonomer and polymerizing the at least one non-functional comonomer with TFE and the at least one functional comonomer.

50. The process of claim 39, wherein the functional groups are carbonyl halide.

51. The process of claim 39, wherein the functional groups are phosphonyl halide.

52. The process of claim 39, wherein the functional groups are sulfonyl halide.

53. The process of claim 39, wherein the functional groups are a carboxylic acid ester.

43. A process comprising

a) polymerizing TFE and at least one comonomer comprising a functional group to form a functional TFE copolymer having a multiplicity of functional groups that are pendant to the polymer chain;

b) expanding the functional TFE copolymer to form an expanded TFE copolymeric material having functional groups and a microstructure characterized by nodes interconnected by fibrils; and

c) reacting the functional groups after the step of expanding the functional TFE copolymer to change a chemical or physical property of the expanded functional TFE copolymer material.

44. The process of claim 43, wherein the functional groups of the expanded TFE copolymeric material are initial functional groups and at least a portion of initial functional groups are reacted to form a secondary functional group that is different from the initial functional group.

45. The process of claim 43, wherein the functional groups of the expanded TFE copolymer are reacted to crosslink the expanded functional TFE copolymer.

46. The process of claim 43, wherein the functional groups of the expanded TFE copolymer are reacted to crosslink the expanded functional TFE copolymer with another material.

47. The process of claim 44, wherein at least a portion of the initial functional groups are reacted with a chemical reagent or reactant to form a secondary functional group.

48. The process of claim 44, wherein the step of reacting is a chemical reaction.

49. The process of claim 43, wherein the initial functional group is an acid halide or an ester that is reacted by hydrolysis to form a second functional group that is an acid.

54. The process of claim 44, wherein the initial functional group is an ester that is reacted with an alcohol to form the secondary functional group that is a different ester.

55. The process of claim 44, wherein the initial functional group is an ester or carboxylic acid that is reacted with NH₃ to form a second functional group that is an amide.

56. The process of claim 44, where in the initial functional group is a nitrile that is reacted with NH₃ to form amidine.

57. The process of claim 44, wherein the initial functional group is a nitrile that is reacted with aminopropyl trimethoxy silane to form a secondary functional group that is an amidine.

58. The process of claim 44, wherein the initial functional group is a nitrile that is reacted by hydrolysis to form a second functional group that is an amide or a carboxylic acid.

59. The process of claim 44, wherein the initial functional group is acid halide or carboxylic acid that is reacted with R—

NH₂ to form amides where R is alkyl or fluoroalkyl.

60. The process of claim 44, wherein the reactant is a biochemical.

61. The process of claim 60, wherein the biochemical is a carbohydrate.

62. The process of claim 61, wherein the carbohydrate is polysaccharide.

63. The process of claim 62, wherein the polysaccharide is chitin, glycogen or heparin.

64. The process of claim 60, wherein the biochemical is a protein.

65. The process of claim 64, wherein the protein is an enzyme.

66. The process of claim 60, wherein the biochemical is a nucleic acid.

67. The process of claim 66, wherein the nucleic acid is DNA.

68. The process of claim 66, wherein the nucleic acid is RNA.

69. The process of claim 60, wherein the biochemical is a lipid.

70. The process of claim 69, wherein the lipid is a steroid.

71. The process of claim 69, wherein the lipid is a hormone.

72. The process is claim 47, wherein the reactant is a synthetic polymer.

73. The process of claim 68, wherein the synthetic polymer is selected from TFE-PMVE-8CNVE, TFE-VDF-HFP-8CNVE, poly(vinyl acetate), poly(vinyl alcohol), poly(ethylene glycol), poly(propylene glycol), poly(ethylene imine), poly(ethyl acrylate), poly(acrylic acid), poly(acrylonitrile), poly(ethylene vinyl acetate), polyethylene vinylalcohol, poly(acrylamide), poly(n-butyl isocynate), poly(dimethylsiloxane), poly(lactic acid), poly(methacrylonitrile), and poly(L-lactide).

74. The process of claim 43, wherein the reaction is a reduction reaction of nitrile functional groups to form an amine.

75. The expanded functional TFE copolymer material made by the process of claim 43.

76. The expanded functional TFE copolymer material made by the process of claim 44.

77. A process comprising

a) providing an expanded polymeric material having a microstructure characterized by nodes interconnected by fibrils wherein the polymer is a functional TFE copolymer of TFE and at least one fluorinated comonomer comprising nitrile functional groups pendant to the polymer chain;

and

b) reacting the functional groups to form an expanded TFE copolymer containing triazine groups.

78. A hydrophilic expanded polymeric material comprising a functional TFE copolymer material comprising a microstructure characterized by nodes interconnected by fibrils, wherein the functional TFE copolymer material comprises a functional copolymer of TFE, PSVE and sulfonic acid pendant to the polymer chain.

79. A composite comprising an expanded functional TFE copolymer of TFE and 8 CNVE wherein the expanded TFE copolymer is cross linked with a fluoroelastomer.

80. A cross linked expanded polymeric material comprising a functional copolymer of TFE and a cyano vinyl ether having cyano groups that are pendant to the polymer chain that is expanded and reacted to form a triazine structure.

81. A composite comprising an expanded functional TFE copolymer material characterized by nodes interconnected by fibrils comprising a copolymer of TFE and at least one comonomer having a carboxylic acid functional group that is pendant to the polymer chain, and a polysaccharide containing a hydroxyl functional group wherein the composite comprises an ester bond between the expanded functional TFE copolymer material and polysaccharide.

82. The composite of claim 81 wherein the polysaccharide is heparin.