NaOH/Urea-Compatible Chitosan/Carboxymethylcellulose Films: Orthogonal Optimization of Packaging Properties

Area of Science:

• Materials Science
• Polymer Science
• Biomaterials Engineering

Background:

• Chitosan (CS)-based films show promise for biodegradable packaging.
• Limitations in barrier and mechanical properties hinder practical use of CS films.

Purpose of the Study:

• To develop and optimize CS/carboxymethyl cellulose (CMC) composite films.
• To improve the functional properties of biodegradable packaging materials.

Main Methods:

• CS/CMC composite films prepared using a NaOH/urea alkaline system.
• Optimization of component ratios via L16(44) orthogonal array design.
• Characterization using FTIR, XRD, and mechanical/barrier property testing.

Main Results:

• Stable physical crosslinks formed between CS and CMC via hydrogen bonding.
• Significantly enhanced mechanical strength (46.08 MPa tensile strength, 68% elongation at break).
• Improved thermal stability (304 °C max decomposition temp) and barrier properties (WVTR: 0.26 × 10-5 g/(m2·h·Pa), OTR: 1.12 × 10-4 g/(m2·s)).

Conclusions:

• The optimized CS/CMC composite film offers excellent functional properties.
• NaOH concentration was the most influential factor on film performance.
• This biodegradable composite presents a sustainable alternative to petroleum-based packaging.