Synthesis and Characterization of PLA/Biochar Bio-Composites Containing Different Biochar Types and Content

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Poly(lactic acid) (PLA) is a biodegradable polymer with growing applications.
• Biochar (BC) is a carbon-rich material produced from pyrolysis, offering potential as a filler.
• Developing effective methods to combine PLA and BC into advanced bio-composites is crucial for sustainable materials.

Purpose of the Study:

• To synthesize and characterize novel poly(lactic acid)/biochar (PLA/BC) bio-composites.
• To investigate the effect of biochar properties and content on PLA's structure and properties.
• To explore the potential of in situ ring-opening polymerization (ROP) for creating well-dispersed PLA/BC bio-composites.

Main Methods:

• In situ ring-opening polymerization (ROP) of lactide in the presence of two types of biochar (SWP550 and SWP700).
• Characterization using techniques such as transmission electron microscopy (TEM) and dielectric spectroscopy.
• Evaluation of thermal stability, decomposition kinetics, and mechanical properties via tensile testing.

Main Results:

• Successful synthesis of PLA/BC bio-composites with evidence of PLA-BC bonding and reduced molar mass.
• Biochar was found to be well-dispersed at the nanoscale within the PLA matrix.
• Strong PLA/BC interactions led to increased glass transition temperature (Tg) and suppressed crystallizability, with effects more pronounced for SWP700 biochar.
• Bio-composites exhibited good thermal stability and slightly enhanced mechanical properties at low BC content (1-5 wt%).

Conclusions:

• In situ ROP is an efficient method for producing PLA/BC bio-composites with nanoscale biochar dispersion.
• The strong interactions between PLA and BC significantly influence the thermal and mechanical properties of the bio-composites.
• These bio-composites demonstrate potential for applications requiring enhanced thermal stability and tailored mechanical performance.