Reinforced PHA/CNC Biocomposites in Extrusion-Based Additive Manufacturing

Area of Science:

• Materials Science
• Polymer Science
• Biotechnology

Background:

• Polyhydroxyalkanoate (PHA) is a biodegradable biopolymer suitable for 3D printing.
• Its mechanical properties are inferior to conventional petroleum-derived polymers, limiting applications.
• Cellulose nanocrystals (CNC) offer potential for reinforcing biopolymers.

Purpose of the Study:

• To synthesize and characterize PHA/CNC nanobiocomposites for 3D printing.
• To evaluate the effect of CNC incorporation on mechanical, rheological, thermal, and structural properties.
• To determine the optimal CNC concentration for enhanced performance.

Main Methods:

• Synthesis of PHA/CNC nanobiocomposites with varying CNC concentrations (0.5-2.5 wt %).
• Filament extrusion and 3D printing of nanobiocomposite samples.
• Mechanical, rheological, thermal, and structural analyses (including micro-CT).

Main Results:

• Incorporation of CNC significantly improved flexural strength (+23.3%), flexural modulus (+20.8%), and Young's modulus (+47.3%).
• Homogeneous CNC dispersion was confirmed; thermal and rheological properties remained largely unchanged.
• Optimal performance was achieved at 0.5 wt % CNC, enhancing mechanical properties and 3D print quality (porosity, geometric accuracy).

Conclusions:

• PHA/CNC nanobiocomposites represent a promising class of high-performance biodegradable materials for 3D printing.
• These materials offer a sustainable alternative to petroleum polymers in biomedical, packaging, and structural applications.
• Additive manufacturing of these nanobiocomposites can reduce environmental impact.