Hyperbranched Poly(ether-siloxane)s Containing Ammonium Groups: Synthesis, Characterization and Catalytic Activity.

Area of Science:

• Polymer Chemistry
• Catalysis
• Green Chemistry

Background:

• Hyperbranched polyglycerols (HPGs) are versatile polymers with tunable properties.
• Developing efficient and recyclable catalysts for CO2 conversion is crucial for sustainable chemistry.

Purpose of the Study:

• To synthesize novel aminated hyperbranched polyglycerols (Amm-HBPGs) with specific end-groups (siloxane or hydroxyl).
• To evaluate the catalytic activity of these Amm-HBPGs in the addition of CO2 to oxirane for ethylene carbonate synthesis.

Main Methods:

• Anionic ring-opening copolymerization of a phthalimide-epoxy monomer with glycidol.
• Post-polymerization modifications including hydrosililation, hydrazinolysis, and quaternization.
• Characterization using NMR, FTIR, and elemental analysis.
• Catalytic testing for CO2 cycloaddition to oxirane.

Main Results:

• Successfully synthesized siloxane- and hydroxyl-terminated Amm-HBPGs.
• Both catalysts demonstrated effectiveness in CO2 addition to oxirane.
• Hydrophilic catalysts showed higher efficiency but produced ethylene glycol byproduct.
• Siloxane-containing catalysts were easily separable and showed high potential for CO2 valorization.

Conclusions:

• Novel Amm-HBPGs with tunable end-groups were synthesized efficiently.
• These polyglycerols serve as effective catalysts for CO2 conversion into ethylene carbonate.
• Siloxane-functionalized Amm-HBPGs offer advantages in recyclability and potential for industrial application in CO2 utilization.