Chemical Upcycling of Polybutadiene Into Polyolefin-Based Dynamic Covalent Polymer Networks

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Chemistry

Background:

• Non-renewable petrochemical feedstocks are unsustainable for specialty polymers.
• Waste commodity thermoplastic polymers offer an alternative feedstock.
• Upcycling waste polymers into advanced materials is crucial for sustainability.

Purpose of the Study:

• To upcycle high molar mass polybutadiene into reprocessable thermoset materials.
• To create dynamic covalent polymer networks (DCPNs) with recyclability.
• To demonstrate a sustainable strategy for polymer waste utilization.

Main Methods:

• Chemically cleaving polybutadiene into low molecular weight α,ω-dienes via partial hydrogenation and ethenolysis.
• Incorporating these dienes into a thiol-ene cured thermoset using multifunctional thiols.
• Demonstrating dynamic covalent behavior through alkylation of thioether linkages.

Main Results:

• Successfully produced reprocessable thermoset materials from polybutadiene waste.
• Established that thioether linkages enable dynamic covalent behavior at elevated temperatures.
• Rheological and reprocessing experiments confirmed the material's recyclability and reshaping capabilities.

Conclusions:

• High molar mass polybutadiene can be effectively upcycled into specialty polyolefin-based thermosets.
• The developed strategy enables the creation of dynamic covalent polymer networks (DCPNs) with significant recyclability potential.
• This approach presents a viable "upcycling" paradigm for bulk polymer waste, promoting sustainable material design.