Study On Dissolution Process Of Feather And Down And The High-value Application Of Its Protein

Feather and down is a fibrotic protein,which keratin content of up to 80%.Keratin has a stable space network structure,compact regions of crystallline,arranged in the molecular chain because the peptide chain contains a large number of-S-S-bond cross-linking and intermolecular hydrogen bonds,ionic bonds and ester bonds and other chemical bonds.This makes the feather keratin difficult to dissolve,which has brought problems to the dissolution,extraction,development and application of feather and down.At present,feather and down has rich source and low prices all over the world,but only fewer parts are used as fillers and decorations,most of which are discarded and are not used properly.This is not only a great waste of protein resources,but also cause great environmental pollution.Now the environmental problems are increasingly serious,the gradual lack of resources,continue to waste protein of feather and down is clearly not meet the road of sustainable development.So it’s imminent to develop the feather and down abandoned.The products of feather and down by strong alkali,biological enzymes and other methods to dissolve are mostly low molecular weight protein,which have low yield,high cost of solvent and the environment pollution,these limits the development and utilization of feather and down.Ionic liquid with non-volatile,non-toxic,easy to recover and strong solubility and other characteristics received great attention as a rising green solvent,among which imidazole ionic liquids shows great advantages in terms of dissolving protein.Based on the forefront of the development of eco-textile and processing technology,this paper aims to protect the human ecological environment as a prerequisite and realize the full utilization of resources to explore the green and efficient use of waste feather and down.It is first describes the definition,morphology,micro-molecular structure and the value to use of feather and down,which lists the extraction methods and the main problems of feather keratin,describes the developmen,synthetic methods of ionic liquids and protein solubility,establishes the research purpose and research content of this thesis.Second,the ionic liquid with imidazole structure named 1-allyl-3-methylimidazolium chloride([Amim]Cl for short)was synthesized and characterized by UV-Vis and FT-IR.It explored the dissolution of waste feather and down in three different dissolution systems of ternary solvents(CaCl2/H2O/C2H5OH),lithium bromide and ionic liquids.The results show that the ternary solvent,lithium bromide can only partially dissolve feather and down,and the dissolution time is long,the molecular weight of the product after dissolution is low.But the feather and down can be completely dissolved in the ionic liquid in a short period of time,and the obtained product has a high molecular weight,while the energy saving process advantages.The final selection of the ionic liquid for the solvent dissolves the feather keratin,The maximum solubility of ionic liquid to feather and down protein was investigated.The results show that the feather and down powder can be completely dissolved in[Amim]Cl at 90℃,the solubility is up to 11%.In this paper,the spectral characteristics of feather and down protein and the crystal structure after regeneration were investigated.The results showed that the disulfide bond was interrupted during the dissolution process,which did not destroy the protein conformation,had the characteristic of protein absorption,and the regenerated protein was mainly amorphous amorphous structure.Thirdly,it is based on the characteristics of UV-Vis spectrum of feather and down at 312nm,and the method of protein quantitative analysis is constructed.The formula is Y=0.2446X+0.9067,where Y is the absorbance,X is feather and down protein concentration,the correlation coefficient R=0.9883.And it is verified by the accuracy of the equation,the relative standard deviation RSD range of 0.68%-2.28%.What show that the concentration of the target product in the solution using this standard curve equation has a high accuracy,at the same time,the stability of the equation was verified,the relative standard deviation RSD range of 0.76%-3.37%.This indicates that the feather and down protein has good stability in ionic liquid,and the standard curve equation has good reproducibility.Finally,the composite membrane of regenerated feather protein(FP for short)and polyvinyl alcohol(PVA for short)was studied.Through the different ratio of composite membrane was prepared based on wet-filming process.Then,the structure of membranes was characterized by FT-IR and SEM,and its optical and photooxidation aging property was analyzed.The results showed that the FP and PVA department of physical integration,did not produce new chemical bonds,smooth surface composite membrane is smooth,no obvious holes and cracks and other defects.The system test of the composite membrane absorption,dynamic and static contact angle,light transmittance,mechanical and light aging properties,the results show that the composite membrane with the increase of FP content,water absorption decreased,water absorption rate decreased from 471%to 202%.The hydrophilic composite membrane decreases with the increase of FP content.The wavelength of visible light the scope of the transmittance of composite membranes with the increase of FP content decreased from 100%to 70%.The mechanical properties gradually decreased with the increase of FP content,tensile strength and elongation reach 5.57MPa minimum and 52.7%in UV light conditions,the mechanical properties of composite membranes have decreased after light breaking strength loss rate of 26.75%.