Quantitative study on the performance of CMCS/SA composite fibers by regulating the hydrogen bonding proportions

Intermolecular hydrogen bonds play an important role in the carboxymethyl chitosan/sodium alginate (CMCS/SA) composite spinning solution and composite fiber. In this study, we prepared a CMCS/SA composite fiber with various intermolecular hydrogen bonding (inter-MHB) proportions via a physical blending method. First, we studied quantitatively the effect of the inter-MHB proportions on the rheological property of the spinning solution and microstructure of the composite fiber. The apparent viscosity of the CMCS/SA composite solution decreased with the increase in the shear rate; however, it increased with the increase in the inter-MHB proportion. The crystallinity and surface roughness of the CMCS/SA composite fibers decreased with the inter-MHB proportion rising, as characterized by XRD and SEM analyses. Furthermore, we quantitatively constructed the relationship between the inter-MHB proportions and the performance of the CMCS/SA composite fibers. As the inter-MHB proportion increased, the tensile strength and modulus of the CMCS/SA composite fibers were enhanced significantly; the thermal stability of the CMCS/SA composite fibers was also improved slightly, as characterized by TGA; the hydrophilicity of the CMCS/SA composite fibers decreased slightly, as characterized by the contact angle test. Therefore, we can improve the viscosity, tensile strength, crystallization, thermal decomposition temperature, and hygroscopicity of CMCS/SA composite fibers by quantitatively regulating the inter-MHB proportions. This work also provides a theoretical and application basis for the study of related composite systems and fibers.