Pseudo-dry-spinning of chitosan

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Textile Engineering

Background:

• Chitosan, a biopolymer derived from chitin, is widely used in biomedical and industrial applications.
• Traditional chitosan processing often involves harsh organic solvents and cross-linking agents, posing environmental and safety concerns.
• Developing greener, solvent-free processing methods for chitosan is crucial for sustainable manufacturing.

Purpose of the Study:

• To develop and evaluate a pseudo-dry-spinning process for producing chitosan fibers.
• To eliminate the need for organic solvents and cross-linking agents in chitosan fiber fabrication.
• To assess the impact of the process on chitosan's molecular weight and fiber morphology.

Main Methods:

• Utilized highly deacetylated chitosan from squid pens with a high molecular weight (540,000 g/mol).
• Dissolved chitosan in an acetic acid aqueous solution (2.4% w/w) for stoichiometric protonation.
• Employed gaseous ammonia for coagulation, followed directly by hot air drying, bypassing aqueous washing baths.

Main Results:

• The pseudo-dry-spinning process successfully produced chitosan fibers without organic solvents or cross-linking agents.
• Chitosan fibers exhibited preserved high molecular weight (350,000 g/mol) after 2 months of storage.
• The process resulted in smooth, regular, and uniformly striated fiber surfaces.
• No significant degradation of polymer chains was observed during the pseudo-dry-spinning process.

Conclusions:

• The developed pseudo-dry-spinning method is an effective and environmentally friendly approach for chitosan fiber production.
• This technique preserves the integrity and high molecular weight of chitosan, making it suitable for advanced applications.
• The absence of organic solvents and cross-linking agents offers a sustainable alternative to conventional methods.