Cellulose and chitin composite materials from an ionic liquid and a green co-solvent

Area of Science:

• Materials Science
• Biochemistry
• Sustainable Chemistry

Background:

• Cellulose and chitin are abundant biopolymers with significant potential for material applications.
• Developing sustainable methods for processing these biopolymers is crucial for reducing environmental impact.
• Ionic liquids offer unique solvent properties for dissolving and processing biopolymers.

Purpose of the Study:

• To develop a novel method for preparing cellulose/chitin composite materials.
• To investigate the structural, mechanical, and surface properties of these composites.
• To utilize biosourced and sustainable solvents for biopolymer processing.

Main Methods:

• Dissolution of cellulose and chitin using 1-butyl-3-methylimidazolium acetate and γ-valerolactone.
• Characterization using element analysis, FTIR spectroscopy, X-ray diffraction (XRD), and mechanical testing.
• Assessment of hydrophobicity via water contact angle measurements.

Main Results:

• The chitin in the composite maintained an average degree of acetylation of 82.5%, indicating no significant deacetylation.
• X-ray diffraction revealed an increase in crystallinity up to 59% with higher chitin content, and crystallite size up to 3 nm.
• Mechanical tests showed a maximum tensile stress of 4.7 MPa, elastic modulus of 27.4 MPa, and elongation at break of 78.7% for composites with 80 wt% chitin.
• Water contact angle measurements demonstrated increased hydrophobicity with the addition of chitin.

Conclusions:

• A sustainable method for producing cellulose/chitin composites was successfully developed.
• The composites exhibit tunable crystallinity and improved mechanical properties with increasing chitin content.
• The incorporation of chitin enhances the hydrophobicity of the cellulose-based materials, opening avenues for novel applications.