PLA Biocomposites Reinforced with Cinnamon-Treated Flax Fibers.

Area of Science:

• Materials Science
• Polymer Science
• Biocomposites

Background:

• Polylactic acid (PLA) biocomposites offer sustainable alternatives.
• Flax fibers are a promising reinforcement material.
• Improving interfacial adhesion and functionality is crucial for biocomposite applications.

Purpose of the Study:

• To investigate the effect of trans-cinnamic acid (TC) modification on flax fibers.
• To evaluate the structural, thermal, viscoelastic, surface, and antibacterial properties of PLA/flax biocomposites.
• To establish structure-property relationships influenced by TC concentration.

Main Methods:

• Preparation of PLA biocomposites with flax fibers modified by varying TC concentrations (1-20%).
• Characterization using Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), and Scanning Electron Microscopy (SEM).
• Assessment of surface wettability (water contact angle) and antibacterial activity against *Escherichia coli* and *Staphylococcus aureus*.

Main Results:

• Moderate TC modification enhanced interfacial adhesion and thermo-mechanical performance.
• Increased surface hydrophobicity was observed at 5% and 10% TC concentrations.
• Significant antibacterial activity (R ≥ 6) was achieved with 10% and 20% TC concentrations.

Conclusions:

• Trans-cinnamic acid concentration is a key factor in tuning the properties of PLA/flax biocomposites.
• TC modification effectively improves mechanical reinforcement and imparts antibacterial functionality.
• Optimized TC concentrations enable tailored biocomposite performance for specific applications.