Preparation Of Carrageenan Fiber By Metal Ion Pre-crosslinking Method And Its Propertie

Carrageenan fiber is a new type of seaweed fiber spun by wet spinning process.Because of its good biocompatibility,biodegradability and excellent self-flame retardant,carrageenan fiber has a broad application prospect in clothing textile,daily household and medical supplies.However,the hydrophilic swelling of carrageenan macromolecules and the easy gelation of carrageenan solution affect the fluidity of the spinning dope,and there are uneven molecular distribution and irregular molecular chain arrangement in the spinning dope.In addition,the contact time between the spinning dope and coagulation bath and stretching bath,which limits the effective combination of metal ions and carrageenan molecular chains.Due to the above reasons,the mechanical properties of carrageenan fibers are poor and the application range is affected.Therefore,the preparation of high-strength carrageenan fibers has always been a hot topic in the research field of functional seaweed fibersBased on the alginate fiber ionic crosslinking theory research,this article aiming at the structural feature of carrageenan fibers and the lack of traditional craft,by accepting the optimized configuration of carrageenan molecular chain,the introduction of trace metal ions in the process of spinning dope preparation,building accepting the structure in the preparation of functional carrageenan fibers,high strength and reveal the relationship between its microstructure and macro properties.The specific research contents are as follows:Ba²⁺pre-crosslinked structure was constructed by adding BaCl₂ into carrageenan spinning dope.The experimental results show that Ba²⁺pre-crosslinking degree is optimal when the mass fraction of Carrageenan is 8.0 wt%,the viscosity of spinning dope is 32193 m Pa?s,and the average particle size is 1475 nm.In addition,the preparation time of spinning dope was shortened from 2.5 h to 1 h,making the preparation process simpler and more efficient.On this basis,coagulation bath and stretching bath suitable for Ba²⁺pre-crosslinking wet spinning was selected.By comparing the surface morphology,fiber forming mechanism and property characterization,it was found that the fiber prepared by low concentration BaCl₂solution had better mechanical properties and fracture strength of 1.61 c N/dtx.Ba²⁺pre-crosslinked carrageenan fiber has excellent self-flame retardancy and limit oxygen index is 32.They showed good hydrophilicity in deionized water and normal saline,with water absorption of 649.2%and 574.3%,respectively.This work provides a new way to optimize the properties of ion pre-crosslinked carrageenan fibers.In addition,the coordination bond type pre-crosslinked structure unit was constructed in the spinning dope by using the coordination of Al³⁺.A new type of Al³⁺pre-crosslinked carrageenan fiber was prepared by wet spinning.The stable pre-crosslinked structure endowed the new fiber with excellent properties.The results showed that the optimal pre-crosslinking degree was obtained when the Al³⁺addition was 3.0 m M,the viscosity was 52696 m Pa?s,and the average particle size was 1896nm.All the properties of the new fiber have been improved obviously,the breaking strength has been increased to 1.77 c N/dtx,the limit oxygen index is up to 49,and the mass loss in the combustion process is gentle.It is a kind of carrageenan fiber with excellent comprehensive properties.In this part,the bonding relationship between Al³⁺and carrageenan molecules in the fiber forming process was revealed,which expanded from the traditional single ionic bond type to the coexistence of ionic and coordination type,promoting the industrialization of carrageenan fibers.