Extrusion of polyolefins with phb-containing high microbial protein biomass for sustainable packaging

Overview

This solution offers a sustainable method for producing biodegradable polymer materials by directly extruding polyhydroxybutyrate (PHB) containing high microbial protein biomass with polyolefins. Traditional PHB production requires energy-intensive extraction and recovery of the polymer from bacterial cells, increasing the carbon footprint despite the material's biodegradability. By skipping the extraction step and using the PHB-biomass complex directly in extrusion with polyolefins and other biodegradable polymers such as PBAT, PLA, and PCL, this approach reduces processing energy while delivering functional bio-based materials.

Preliminary investigations have demonstrated successful film production with smooth, glossy surfaces, a critical quality characteristic for packaging applications. Glycerol has been incorporated as a plasticizer to enhance mechanical properties and barrier performance. The technology supports circularity and biodegradability objectives, making it relevant for sustainable packaging, mulch films, and construction films.

Technical specifications

Key features:

• Direct use of PHB with high microbial protein biomass eliminates the need for energy-intensive PHB extraction and recovery
• Compatible with biodegradable polymers including PBAT, PLA, PCL, and pure PHB, as well as polyolefins such as polypropylene (PP) and polyethylene (PE)
• Glycerol and other plasticizers (sorbitol, PEG, sucrose) improve mechanical properties and gas/water vapor barrier performance
• Processing methods include twin-screw extrusion, injection molding, and compression molding
• Produces smooth, glossy films suitable for food packaging and other film applications
• Supports circularity by incorporating pre-treated post-consumer mixed plastics as primary feedstock

Technology readiness level

The technology is at the prototype development stage. Preliminary product development has demonstrated successful film production using PHB-containing microbial protein biomass blended with biodegradable polymers and glycerol. Future validation will involve blending with polyolefins (PP, PE) and comprehensive characterization using DSC, FTIR, tensile testing, and gas and water vapor permeability testers over an approximately one-year study period. The research team is actively seeking partnerships to advance prototype material development, particularly for food packaging, mulch films, and construction films.