Composite materials containing keratin
The application describes materials derived from keratin proteins in combination with polymers, either as intimate mixtures with water soluble polymers, or as chemically bound copolymers. The keratin protein is a specific keratin protein fraction, and is preferably intact, s-sulfonated and from the intermediate filament protein family. The application also describes the process for production of these materials.
1. A film, fiber or membrane comprising an intimate mixture of S-sulfonated keratin protein and a water soluble polymer, and a chemical cross-linking agent, the water soluble polymer selected from the group consisting of:
(a) poly(vinyl alcohol) (PVA) and
(b) poly(vinyl pyrrolidone) (PVP).
2. A film, fiber or membrane according to claim 1 wherein the S-sulfonated keratin protein is a S-sulfonated keratin protein fraction.
3. A film, fiber or membrane according to claim 2 in which the S-sulfonated keratin protein fraction is from the intermediate filament protein family.
4. A film, fiber or membrane according to claim 1 in which the S-sulfonated keratin protein is intact.
5. A method for making a material comprising:
(a) mixing a S-sulfonated keratin protein and a water soluble polymer to form an intimate mixture, the water soluble polymer selected from the group consisting of:
(a) poly(vinyl alcohol) (PVA) and
(b) poly(vinyl pyrrolidone) (PVP)
(b) casting the intimate mixture so produced; and
(c) drying to create a material.
6. A method for making a material comprising:
(a) mixing a S-sulfonated keratin protein, a chemical cross-linker, and a water soluble polymer to form an intimate mixture, the water soluble polymer selected from the group consisting of:
(a) poly(vinyl alcohol) (PVA) and
(b) poly(vinyl pyrrolidone) (PVP); and
(b) extruding the intimate mixture produced from step (a) into a coagulation bath through a process of wet spinning.
7. A method for improving the physico-mechanical properties of the materials produced by claim 5 , comprising introducing a cross-linker agent to form disulfide bonds and thus remove sulfonate functionalities.
8. A method according to claim 7 in which the cross-linking agent used as a reductant is a thiol or thioglycollate salt.
9. The method according to claim 7 in which the physico-mechanical properties are wet and dry strength.
10. A method according to claim 8 in which the thioglycollate salt is ammonium thioglycollate.
11. The method according to claim 5 or 6 wherein the S-sulfonated keratin protein is a S-sulfonated protein fraction.
12. The method according to claim 11 wherein the S-sulfonated keratin protein fraction is from the intermediate filament protein family.
13. The method according to claim 5 or 6 , wherein the S-sulfonated keratin protein is intact.
14. A method of improving the wet strength properties of the materials produced by the method of claim 5 , comprising incorporating a cross-linking agent into them.
15. A method according to claim 14 in which the cross-linking agent is a protein in the intimate mixture.
16. A method according to claim 14 in which the cross-linking agent is selected from the group consisting of formaldehyde and glutaraldehyde.
17. A process for improving the mechanical properties of a material produced by a method of claim 5 or 6 , comprising heat treating the composite matrix to enhance its crystalline properties.
18. An S-sulfonated keratin protein derivative material in which the keratin protein derivative is chemically bonded to a monomer or polymer material selected from the acrylate, epoxide or anhydride group.
19. The film or membrane of claim 1 , further comprising a plasticizer.
20. The film or membrane of claim 19 , wherein the plasticizer is glycerol or polyethylene glycol.
21. The film or membrane of claim 1 , wherein the cross-linking agent is, formaldehyde, glutaraldehyde, 1-ethyl-3-(dimethylaminopropyl)carbodiimide, dimethylsuberimidate, or N,N′-methylenebisacrylamide.