Production of biopolymer film, fibre, foam and adhesive materials from soluble S-sulfonated keratin derivatives
Film, fibre, foam and adhesive materials are produced from soluble S-sulfonated keratins. Once formed, the films, fibres, foams or adhesives are treated to modify the properties of the materials, in particular to improve the wet strength of the materials. Treatments used include removal of the S-sulfonate group by treatment with a reducing agent, treatment with an acid or treatment with a common protein crosslinking agent or treatment with a reduced form of keratin or keratin protein. The films are made by solvent casting a solution of S-sulfonated keratin proteins, the foam made by freeze-drying a solution of S-sulfonated keratin proteins and the fibres made by extruding a solution of a S-sulfonated keratin protein.
1. A porous solid foam or an adhesive material derived from S-sulfonated proteins.
2. The foam or adhesive material as claimed in claim 1 where the S-sulfonated proteins comprise S-sulfonated wool keratin intermediate filament proteins.
3. The foam or adhesive material as claimed in claim 1 or claim 2 wherein the keratin proteins are reconstituted from a solution.
4. The material as claimed in claim 1 or claim 2 which is a foam.
5. The material as claimed in claim 1 or claim 2 which is an adhesive.
6. The material of claim 5 which is in the form of an aqueous solution.
7. The adhesive as claimed in claim 5 comprising a solution of S-sulfonated keratins.
8. The adhesive as claimed in claim 5 , also comprising a reductant selected from the group consisting of phosphine, thiol and mixtures thereof.
9. An adhesive as claimed in claim 5 constituting a two pot adhesive in which one component is solution of S-sulfonated keratin protein and other component is solution of reduced keratins or reduced keratin peptides, that on combination react to form a crosslinked network and subsequently an adhesive.