Mechanical and Rheological Evaluation of Polyester-Based Composites Containing Biochar

Area of Science:

• Materials Science
• Polymer Science
• Composite Materials

Background:

• Biodegradable polymers offer sustainable alternatives in composite applications.
• Biochar, a carbon-rich material, is explored as a filler to modify polymer properties.
• Understanding filler content effects is crucial for optimizing composite performance.

Purpose of the Study:

• To investigate the mechanical property changes in biodegradable composites with varying biochar content.
• To evaluate the influence of biochar as a filler on Poly(1,4-butylene adipate-co-1,4-butylene terephthalate)/polylactide (PBAT/PLA) and Polylactide/poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate] (PLA/P(3HB-co-4HB)) matrices.
• To determine the optimal composition for specific mechanical requirements.

Main Methods:

• Fabrication of PBAT/PLA/biochar and PLA/P(3HB-co-4HB)/biochar composites with 0-30 wt% biochar.
• Mechanical testing including tensile tests and Charpy impact tests.
• Rheological analysis to determine complex viscosity.

Main Results:

• Tensile modulus increased up to 100% with 30 wt% biochar.
• Elongation at break decreased significantly (up to 65%) with increased biochar.
• Tensile strength decreased in PLA/P(3HB-co-4HB) composites with higher biochar content.
• Impact strength and brittleness increased with biochar content in both matrices.
• Complex viscosity increased with biochar content, while decreasing with angular frequency.

Conclusions:

• Biochar addition significantly alters mechanical properties of biodegradable composites.
• Increased biochar content leads to enhanced stiffness but reduced ductility and toughness.
• The specific biodegradable matrix influences the extent of property changes.
• Careful control of biochar content is necessary for tailoring composite performance.