Hydrogen bonding in chitosan/Antarctic krill protein composite system: Study on construction and enhancement mechanism

The protein model via encoding nucleotide sequences of cDNA for Antarctic krill and conjecture about the effect of AKP on the crystallization of CS. The presence of AKP facilitates the induction of chitosan nucleation to form more microcrystalline structures. At the meantime, the increasing intensity probably attributed to the hydrogen bond formed between CS and AKP to limit the molecular chain curl, which induced crystal growth. [Display omitted] •It gives a new composite solvent to prepare stable CS/AKP composite solution.•It offers a chance to combine both main krill ingredient.•It is the first time to obtain CS/AKP fibers by wet-spinning on a lab-scale machine.•A new method to calculate the degree of deacetylation of chitosan.•Provide CS referenced wavenumbers of the functional groups of FTIR curve fitting. The main of the work concerns the reason for the interpretation of the tensile strength of chitosan (CS) enhanced by Antarctic krill protein (AKP). We found a new mixed solvent, 2 wt% glacial acetic acid, and 2 wt% ethylene glycol aqueous solution, to prepare a stable CS/AKP composite solution. Then we obtained CS/AKP fiber by wet-spinning on a lab-scale wet-spinning machine. The tensile strength of blended fibers is 2.53 cN/dtex in the dry state, which is improved by 11.9% compared with the CS fibers. We found that the increased tensile strength of the blended fibers is relative to the hydrogen bond formed between CS and AKP. Specifically, illustrate the restructured hydrogen bonds in CS/AKP system in Fourier transform infrared curve fitting. The hydrogen bond probably benefits on crystalline growth of CS along the fiber axis and is the main drivable factor in removing the water molecules in blended fibers.