High-Molecular-Weight Biodegradable CO₂/Propylene Oxide/Epichlorohydrin Terpolymers with Outstanding Gas Barrier...

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Polymers

Background:

• Poly(propylene carbonate) (PPC) derived from CO2 shows promise but suffers from poor thermal stability and low glass transition temperature.
• Existing PPC materials limit their application in demanding packaging scenarios.

Purpose of the Study:

• To develop novel PPC-ECH terpolymers with enhanced properties.
• To improve thermal stability, mechanical strength, and barrier performance of PPC.
• To explore a sustainable, metal-free synthesis route for advanced polycarbonates.

Main Methods:

• Terpolymerization of CO2, propylene oxide (PO), and epichlorohydrin (ECH) using multinuclear organoboron catalysts.
• One-pot, metal-free synthesis approach.
• Tuning reaction conditions, monomer ratios, and catalyst parameters to control terpolymer properties.

Main Results:

• Synthesized PPC-ECH terpolymers with molecular weights up to 59.4 kg mol⁻¹, the highest reported.
• Achieved outstanding barrier properties: oxygen permeability of 1.31 cm³ mm⁻² day⁻¹ and water vapor permeability of 0.016 g mm⁻² day⁻¹.
• Enhanced mechanical properties, glass transition temperature, thermal stability, and flame retardancy compared to pure PPC.

Conclusions:

• The developed PPC-ECH terpolymers exhibit a favorable balance of properties, overcoming limitations of traditional PPC.
• The incorporation of ECH preserves biodegradability while significantly improving material performance.
• These terpolymers present a promising sustainable alternative for high-performance packaging materials.