Pretreatment Of Poultry Feather And Preparation And Performance Of Feather Fiber Reinforced Keratin Composite Film

Poultry feather is a natural keratin fiber which is widely sourced,biodegradable and cheap.In China,a large amount of feather fibers are discarded because they are not used reasonably.This not only causes environmental pollution but also wastes protein resources.Therefore,it is particularly important to study the regeneration and utilization of poultry feather.In this paper,chemical and plasma treatments were used on surface of feather fibers to improve the surface binding ability of feather fibers.Feather keratin solution was prepared by the reduction method.The keratin/gelatin/glycerin blend films and keratin/silk fibroin/gelatin/glycerin blended films were prepared,respectively,and structure and properties of the blended films were studied.Then keratin/gelatin/glycerin/feather fiber composite films were prepared to study the influences on structure and properties of feather fiber.It has provided a certain theoretical basis for the application of keratin composite films in coating materials and other fields.Firstly,a mixed solution of calcium chloride,urea and ammonia water was used to perform separation pretreatment and nitrogen low-temperature plasma treatment was used to perform micro-surface treatment on poultry feather,to obtain chemically treated poultry feather,plasma treated poultry feather and chemically and plasma treated poultry feather.The morphology,microstructure,secondary structure,X-ray photoelectron spectroscopy,thermal properties,wetting properties and fiber strength of feather fibers were analyzed.The test results show that after chemical treatment,the biowax on the feather fiber surface has been removed and the division of fiber on feather barbs has become more obvious.A large number of carbon and sulfur elements have been removed from the surface,and the thermal stability and breaking strength are reduced as well.After plasma treatment,the surface of the feather fiber has been etched and oxidized,resulting in the increase of surface roughness,wettability and thermal stability but the decrease of fracture strength.Secondly,keratin/gelatin/glycerin blended films and keratin/silk fibroin/gelatin/glycerin blended membranes were prepared by using keratin extracted form poultry feathers,and the secondary structure,thermal properties,mechanical properties,water content and hot water solubility were analyzed.The results show that glycerin plasticized the blended films and weakened the binding force between protein macromolecular chains,which led to reduction of thermal stability.With the increase of glycerol content,the breaking strength of the blend film decreased from 59.53MPa to about 1MPa,while the elongation at break increased from 3.64%to more than 100%.The silk fibroin caused the secondary structure of the blended film to gradually change from keratin to silk fibroin.The thermal stability of the blended film was higher than that of single keratin and silk fibroin film.The breaking strength of the blended film reached the highest,which was 42.53MPa,when keratin/silk fibroin 50/50 was contained.Silk fibroin can significantly reduce the hot water loss rate,maintain the basic morphological structure and reduce the solubility of the blended film.Finally,keratin/gelatin/glycerin 100/100/40 blended films were used as substrates and poultry feathers were used as the reinforcement to prepare untreated poultry feather composite films,chemically treated poultry feather composite films,plasma treated poultry feather composite films,and chemically and plasma treated poultry feather composite films with different fiber contents.The results showed that the components of the composite film were simply mixed and the addition of feather fibers had no effect on the secondary structure and thermal analysis of composite films.The results of the mechanical property test showed that with the increase of the fiber content,the breaking strength of the composite film increased first and then decreased,while the elongation at break showed the opposite trend.The basic trend of the breaking strength of different composite films with the same fiber content is untreated poultry feather composite film<plasma treated poultry feather composite film<chemically treated poultry feather composite film<chemically and plasma treated poultry feather composite film.The combination of chemical and plasma treatments have increased the degree of fiber separation,surface roughness,and hydrophilicity,thereby enhancing the interface binding ability between feather fibers and the matrix,and have the best enhancement effect among the three fiber treatment methods.