A Modular Post-Polymerization Modification Route to Aminated Polybutadienes for Electrochemical CO₂ Valorization

Area of Science:

• Polymer Chemistry
• Materials Science
• Electrochemistry

Background:

• Post-polymerization modification offers a route to functional polymers with tunable properties.
• Functional polymers are crucial for tailoring catalytic microenvironments, especially for electrochemical CO2 reduction (CO2RR).
• Precise control over functional group incorporation in polymers remains a challenge for optimizing material properties.

Purpose of the Study:

• To develop a modular post-polymerization strategy for functionalizing polybutadiene with primary amines.
• To achieve tunable and selective incorporation of functional groups onto the polymer backbone.
• To investigate the impact of amine functionalization on the electrochemical CO2 reduction reaction (CO2RR).

Main Methods:

• Functionalization of polybutadiene via nitration using tert-butyl nitrite, followed by reduction to primary amines.
• Utilizing 15N-labeling to analyze regioselectivity of functionalization.
• Applying amine-functionalized polybutadiene layers on copper electrodes for CO2 electroreduction studies.

Main Results:

• Achieved tunable nitro incorporation (0.8–18.6%) onto the polybutadiene backbone with high regioselectivity for internal unsaturated bonds.
• Demonstrated successful reduction to primary amines without compromising polymer integrity.
• Observed a scaling relationship between amine functionalization degree and C2 product partial currents in CO2RR.

Conclusions:

• Developed a robust and versatile post-polymerization strategy for precise polymer functionalization.
• The method allows for systematic tuning of polymer properties for energy materials applications.
• Amine functionalization of polybutadiene significantly influences CO2RR selectivity and efficiency.