Effects of sodium salt types on the intermolecular interaction of sodium alginate/antarctic krill protein composite fibers

Sodium alginate (SA) and antarctic krill protein (AKP) were blended to fabricate the SA/AKP composite fibers by the conventional wet spinning method using 5% CaCl2 as coagulation solution. The sodium salt was added to the SA/AKP solution to adjust the ionization degree and intermolecular interaction of composite system. The main purpose of this study is to investigate the influences of sodium salt types (NaCl, CH3COONa, Na2SO4) on the intermolecular interaction of SA/AKP composite fibers. The intermolecular interaction, morphology, crystallinity, thermal stability and mechanical properties of SA/AKP composite fibers were analyzed by fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), x-ray diffraction (XRD), thermogravimetric analysis (TGA). The results show that the types of sodium salt have obvious influences on the content of both β-sheet, intermolecular hydrogen bond, breaking strength and surface morphology in SA/AKP composite fibers, but have a negligible effect on the crystallinity and thermal stability.