Cellulose-keratin polymer based on "thiol-ene" click reaction and ease-to-process performance

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials

Background:

• Cellulose and keratin are abundant biopolymers with potential for material development.
• Existing methods for cellulose-keratin composites often involve harsh chemicals or result in suboptimal properties.

Purpose of the Study:

• To develop a new method for preparing cellulose-keratin (CK) polymer.
• To characterize the structure and properties of the synthesized CK polymer.
• To evaluate the performance of CK films and fibers for potential applications.

Main Methods:

• Preparation of allyl cellulose (AC) in an alkali/urea system.
• Synthesis of CK polymer via UV-initiated "thiol-ene" click reaction between AC and keratin (Ker).
• Characterization using FTIR, XRD, XPS, and NMR; mechanical testing of films and fibers; assessment of functional properties.

Main Results:

• Successful synthesis of AC and CK polymer confirmed by spectroscopic and analytical techniques, preserving keratin integrity.
• CK films exhibited high transmittance, dense morphology, and excellent flexibility, with superior mechanical strength (44.93 MPa) and elongation (22%) compared to previous methods.
• CK fibers demonstrated enhanced mechanical properties (28.8 MPa, 15%) over co-solvent ionic liquid methods, along with excellent moisture absorption and potential for added functionalities (fluorescence, thermochromic, flame retardancy).

Conclusions:

• The "thiol-ene" click reaction provides an efficient route to novel cellulose-keratin (CK) polymers.
• CK materials possess superior mechanical and processing characteristics compared to existing cellulose-protein composites.
• The developed CK fibers show promise for functional textiles with improved comfort and added features.