The Study Of Feather Keratin Regeneration And The Property Of Keratin Fiber

With the strengthening of environmental awareness and the improvement of consumer demand, more and more attention to the research of environmentally friendly new fibers. Regenerated protein fibers obtained in the waste or by-products take advantage of the new material. Keratin is widespread, human and animal epidermis, hair, and hooves, shells, claws, horns of animals. China’s annual output of waste poultry feathers there are more than70million tons, keratin content in feathers can reach85%-89%. Keratin has been widely used in the bio-pharmaceutical industry, textile industry and the animal feed industry. Research new technology to take advantage of these waste resources, not only help to improve the current environmental issues needed to be resolved, but also an important measure to develop new resources rational use of existing resources to achieve recycling of resources as well as to create a conservation-oriented society.Protein which can be used for spinning has its unique requirements, including molecular weight, degree of crystalline, the cross-linking sites, non-toxic, biocompatible, biodegradable and the like, and the natural polymer keratin is entirely consistent. But because the content of disulfide bonds in keratin is rich, so it presents different properties from other proteins, such as the degree of cross-linking and can not readily dissolve. In the keratin fiber molding technology, the copolymerization of keratin and other substances as a means to handle wet spinning method to resolve the shortcomings of poor mechanical properties of keratin alone. Our research and development in this area is still in its infancy, many keratin excellent performances have not been development and utilization, only a few domestic enterprises engaged in the production and application. Keratin as a versatile biological material, there are boundless opportunities and good prospects for development.This subject obtained by changing the content of urea, Na2S2O5and SDS to obtain two different kinds of keratin:keratin solution and regenerated keratin, they are the raw materials of the fiber. The viscosity of the keratin solution was varied between40cp-100000cp, and cross-linked product in200000cp400000cp. By measuring the infrared spectra of the feather, keratin solution and regenerated keratin, and analyzed by software to obtain the hidden peak of their secondary structure. We can found β-sheet is the advantages exist in feather keratin and regenerated keratin; it is, respectively,45.2%and50.8%. In the keratin solution, α-helix is the advantage, to reach41.8%. When keratin solution changing to cross-linked keratin, the α-helix content is reducing, β-sheet is increasing, so the α-helix to β-sheet transformation. By the thermal gravimetric analysis, we found that the keratin weightlessness temperature between100℃-400℃. Also found that, after freeze-drying, the regenerated keratin is advantage to keratin solution with better thermal stability.When the inorganic salts and organic matter as a coagulation bath, the ability of the solidification is:BaCl2=CaCl2> Al2(SO4)3> MgSO4>(NH4)2SO4> KCl> of Na2SO4. When the organic solvent of CH3CH2OH, HCOOH and CH3COOH as coagulation bath, we found the effect of CH3CH2OH and HCOOH is similar, while CH3COOH weaker. And we also found that the organic solvent has better use value compared to salts keratin solution:dosage less, more efficient, more obvious, no stimulation and no toxic effects. While changing the concentration of the coagulating bath, such as CaCl2concentration, with the increase of its concentration, the increase of the solidification effect, and phase separation capacity also increases. As the temperature rises, the coagulation ability of the coagulation bath is gradually increasing; the system is more prone to phase separation. But as reduce appropriately the temperature of the coagulation bath, the compactness of the fiber can be improved, the holes in the fiber cross section can be reduced, the density is increased, the toughness can be improved, enhance the properties of the fibers, so taking into consideration such as cost, operability, we identified the25℃is more advantage.The two different type keratins made into fibers by the appropriate method, and then we studied the mechanical properties. With the increase in the line density of the fiber, the increase in the elongation at break, but the tensile strength at break was gradually reduced. In the experience of how the different line density effect fiber mechanical properties. Different coagulation bath has significant impact on fiber mechanical properties. The fiber solidify in the CaCl2and glycerol bath, the tensile strength is small, and with the increasing of the glycerol content, the tensile breaking strength of the fibers decreases gradually, but the elongation is first increases and then decreases. When CaCl2and acetic acid as the coagulation bath, as the acetic acid concentration increases, the tensile strength at break is also gradually increased, the elongation at break is first increase then decreases. In addition, compared this two coagulation baths, the mechanical properties of the fibers which the acetic acid used as a coagulation bath is better; the fibers have better tensile strength and elongation. The different coagulation bath temperature effect the mechanical properties of the fibers, when the temperature changing from10℃to45℃, the tensile strength, elongation and the Young’s modulus are first increased and then decreased. The time dependency of the mechanical properties of the fibers-stress relaxation experiment confirmed that after acid treatment, the fiber has a better structural stability. By observing the morphology of the surface of the fiber, glycerol and acetic acid used as coagulation bath, the surface characteristics of the fibers preferably.