Polyurethane-grafted graphene oxide from repurposed foam mattress waste

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Materials

Background:

• Polyurethanes (PU) are widely used commodity plastics but pose sustainability challenges due to their thermoset nature, hindering recycling.
• Developing effective recycling and repurposing strategies for polyurethanes is crucial for environmental sustainability.
• Graphene-based nanocomposites offer potential for enhancing polymer properties.

Purpose of the Study:

• To develop a sustainable method for upcycling polyurethane waste into functional graphene-grafted materials (PU-GO).
• To investigate the impact of these PU-GO fillers on the thermal and mechanical properties of polyurethane foams.
• To explore the potential of PU-GO as a sustainable additive for improving polyurethane performance.

Main Methods:

• Utilized dynamic depolymerization under green conditions for a one-pot synthesis of PU-GO nanofillers.
• Synthesized PU-GO with tunable polyurethane to graphene oxide ratios.
• Incorporated PU-GO fillers into bulk polyurethane foam at varying weight percentages (0.25-2.0%) and analyzed thermal and mechanical properties.

Main Results:

• All PU-GO fillers improved thermal insulation, with significant reductions in thermal conductivity (up to 38.5%) observed.
• Composites demonstrated enhanced mechanical properties, including improved durability against fatigue and greater impact resistance at higher filler content.
• Chemical analysis confirmed the incorporation of the polycarbamate hard-segment of polyurethane onto the graphene oxide.

Conclusions:

• The developed dynamic depolymerization method provides a viable route for upcycling polyurethane waste into valuable PU-GO nanofillers.
• PU-GO fillers effectively enhance the thermal insulation and mechanical performance of polyurethane foams.
• These upcycled PU-GO materials show significant promise as sustainable additives for improving polyurethane applications.