Preparation And Study Of Silk Fibroin/Sodium Alginate Composites

Because sodium alginate(SA)fiber has good flame retardancy,biocompatibility,hygroscopic properties and moisturizing properties,it has great application prospect in the fields of textile manufacturing,medical hygiene,but poor mechanical properties of sodium alginate limit its application and scope of application.In this paper,the physical properties of sodium alginate fiber were improved by physical blending and chemical crosslinking,and the mechanical properties of sodium alginate fiber were strengthened to meet the requirements in the fields of textile manufacturing and medical hygiene.(1)Preparation and properties research of silk fibroin/sodium alginate composite fiberIn order to develop mechanical properties of Sodium alginate fiber,the spinning solution of Silk fibroin/Sodium alginate was prepared to obtain the composite fiber of Silk fibroin/Sodium alginate by using wet spinning process.The Apparent viscosity of spinning solution,chemical structure,mechanical properties,microstructure and thermal property of composite fiber were characterized by DV-C display viscosity meter,Fourier Transform Infrared Spectrometer(FTIR),Electronic single fiber strength tester,Scanning Electron Microscopy(SEM),Thermogravimetric Analyzer,and other test methods.The results show that SF/SA spinning solution is pseudoplastic fluid,of which the apparent viscosity increases as a whole with the content of silk fibroin.The structural viscosity index ?? is minimal and spinnability of composite fiber is best when SF content is 10%.Mainly based on the random conformation and helical structure,the extracted SF is connected with SA by the hydrogen-bond.Compared with the pure SA fiber,the addition of SF enhances the mechanical properties of composite fiber,up to 1.6356 CN*dtex-1.There exists obvious groove structure on the surface of composite fiber,which decreases in the crystallization property with the blending of SF.(2)Preparation of chemical cross-linking silk fibroin/aodium alginate fiber and gauzeThe silk fibroin(SF)/sodium alginate(SA)double network composite fiber was prepared by incorporating silk fibroin cross-linked with polyethylene glycol diglycidyl ether(PEGDE)as a cross-linking agent into sodium alginate cross-linked with CaCl2 as a cross-linking agent.The chemical cross-linking modified SF/SA composite fiber was used as the weft yarn and pure cotton yarn as the warp yarn,composite gauze was prepared by the small sample weaving machine.The apparent viscosity of spinning solution and properties of as-prepared crosslinking modified composite fiber and gauze were characterized by DV-C display viscosity meter,FTIR,Electronic single fiber strength tester,SEM,XRD,Electronic fabric strength tester.The results indicate that the apparent viscosity of spinning solution decreases first and then increases as the crosslinking agent was added;while it affected the breaking strength and elongation and the degree of cross linking in the opposite way.More specifically,the breaking strength and crosslinking degree both reach the maximum(2.34 cN/dtex and 55.8%,respectively),when the mass ration of crosslinking agent PEGDE and silk fibroin is 3:1.The higher the degree of crosslinking is,the more significant the trench structure on the surface of crosslinking modified SF/SA composite fiber is and the better for the compatibility of the composite fiber.In addition,hygroscopicity and moisture retention of crosslinking modified composite fiber has improved and the moisture absorption equilibrium time is advanced.Chemical cross-linked modified SF/SA gauze exhibits excellent mechanical properties,water absorption,hygroscopic properties and moisturizing properties,as medical dressings and medical bandages provide excellent prerequisites.