Chemoselective polymerization control: from mixed-monomer feedstock to copolymers

Area of Science:

• Polymer Chemistry
• Catalysis
• Materials Science

Background:

• Controlled polymerization techniques are crucial for designing polymers with specific properties.
• Existing methods often lack selectivity when polymerizing multiple monomers simultaneously.
• Developing catalysts that enable precise control over copolymer composition is an ongoing challenge.

Purpose of the Study:

• To develop a novel chemoselective polymerization method for predictable copolymer synthesis.
• To investigate the use of a dizinc catalyst for the controlled polymerization of caprolactone, cyclohexene oxide, and carbon dioxide.
• To demonstrate the ability to selectively produce polyesters, polycarbonates, or copoly(ester-carbonates) from a single reaction mixture.

Main Methods:

• Utilized a dizinc catalyst system for ring-opening polymerization and carbon dioxide insertion.
• Employed a mixture of caprolactone, cyclohexene oxide, and carbon dioxide as monomers.
• Investigated the influence of zinc-oxygen functionality at the polymer chain end on selectivity.
• Applied exogenous switch reagents to control the polymerization pathway.

Main Results:

• Achieved predictable (co)polymer compositions from a mixture of monomers through chemoselective control.
• Demonstrated the selective synthesis of polyesters, polycarbonates, or copoly(ester-carbonates) using the dizinc catalyst.
• Established that the selectivity is governed by the nature of the zinc-oxygen functionality at the growing polymer chain end.
• Showed that exogenous switch reagents can effectively control the polymerization outcome.

Conclusions:

• A novel chemoselective polymerization strategy offers precise control over copolymer composition.
• The dizinc catalyst system provides a versatile platform for synthesizing diverse polymer architectures.
• This approach enables the tailored production of polyesters, polycarbonates, and copoly(ester-carbonates) with high selectivity.