Tuning the Properties of Xylan/Chitosan-Based Films by Temperature and Citric Acid Crosslinking Agent

Area of Science:

• Materials Science
• Polymer Science
• Biomaterials Engineering

Background:

• Petroleum-based food packaging generates significant environmental waste and microplastic pollution.
• Developing sustainable and biodegradable alternatives is crucial for reducing environmental impact.

Purpose of the Study:

• To create and characterize biobased films from xylan and chitosan polyelectrolyte complexes (PECs).
• To investigate the effects of citric acid concentration and thermal treatment on film properties.
• To assess the potential of these films as environmentally friendly food packaging.

Main Methods:

• Preparation of xylan/chitosan PEC films with varying citric acid (CA) concentrations.
• Thermal treatment of films at 135 °C and 155 °C for 30 or 60 minutes to induce crosslinking.
• Characterization using Fourier Transform Infrared Spectroscopy, Confocal Raman Microscopy, stress-strain tests, contact angle measurements, and thermal stability analysis.

Main Results:

• Thermal treatment significantly improved water resistance and mechanical strength (dry and wet stress-strain).
• Optimal performance was achieved at 155 °C, with 5 wt% CA enhancing strength up to 88 MPa (dry) and 5.6 MPa (wet).
• UV-blocking performance and thermal stability (onset temperature up to 230 °C) were also improved.

Conclusions:

• Thermal treatment of xylan/chitosan films with low citric acid concentrations is an effective strategy to enhance material performance.
• These biobased films demonstrate promising properties for sustainable food packaging applications.
• The developed films offer a viable eco-friendly alternative to conventional petroleum-based packaging materials.