Characterization of Polyhydroxybutyrate-Based Composites Prepared by Injection Molding

Area of Science:

• Materials Science
• Polymer Science
• Sustainable Materials

Background:

• Single-use plastics pose significant environmental challenges due to their non-recyclable and non-biodegradable nature.
• Biodegradable polymers offer a sustainable alternative to conventional plastics, reducing environmental pollution.
• Polyhydroxybutyrate (PHB) is a promising biopolymer for developing eco-friendly materials.

Purpose of the Study:

• To investigate the effects of various additives on the mechanical and thermal properties of polyhydroxybutyrate (PHB)-based composites.
• To evaluate the influence of microspheres, carbon fibers, and polyethylene glycol (PEG) with different molecular weights on PHB composites.
• To assess the feasibility of using injection molding for processing these biodegradable composites.

Main Methods:

• Polyhydroxybutyrate (PHB) composites were prepared with additives including microspheres, carbon fibers, and polyethylene glycol (PEG) of varying molecular weights (2000, 10,000, 20,000).
• Samples were fabricated using injection molding with a custom mold attached to a commercial extruder.
• Characterization involved microscopy, spectroscopy, thermal analysis (e.g., DSC, TGA), and mechanical testing (e.g., hardness, compressibility).

Main Results:

• Addition of carbon fibers and microspheres had a negligible effect on the thermal stability of PHB composites.
• Polyethylene glycol (PEG) demonstrated a slight enhancement in thermal properties, particularly at higher molecular weights.
• All tested composite formulations exhibited a reduction in hardness and compressibility compared to the neat PHB.

Conclusions:

• Injection molding is a viable technique for processing PHB-based composites with various additives.
• The study provides valuable insights into tailoring the properties of PHB composites for specific applications.
• Findings support the advancement and integration of biodegradable plastics into consumer products to mitigate plastic waste.