Controlled Radical Homopolymerization of Representative Cationically Polymerizable Vinyl Ethers

Area of Science:

• Polymer Chemistry
• Organic Synthesis

Background:

• Direct radical homopolymerization of vinyl ethers is challenging due to potential side reactions.
• Existing methods often require specific functional groups or harsh conditions.

Purpose of the Study:

• To develop a facile and efficient direct radical homopolymerization method for vinyl ethers.
• To investigate the roles of hydrogen bonding and cation-π interactions in this polymerization.

Main Methods:

• Water-suspension polymerization using a thermally triggered azo-initiator (dimethyl 2,2'-azobis(2-methylpropionate)) and lithium hydroxide.
• Exploration of controlled polymerization using a dithiocarbamate reversible addition-fragmentation chain transfer (RAFT) agent.

Main Results:

• Achieved near full conversion in direct radical homopolymerization of vinyl ethers without hydroxy groups.
• Demonstrated that hydrogen bonding and Li+ cation-π interactions are crucial for suppressing side reactions and facilitating polymerization.
• Successfully adapted the method for controlled polymerization using RAFT agents.

Conclusions:

• The developed method offers a facile route for direct radical homopolymerization of vinyl ethers in an aqueous system.
• Understanding the interplay of hydrogen bonding and cation-π interactions is key to controlling vinyl ether polymerization.
• This approach provides a foundation for controlled polymerization of vinyl ethers with potential for broader applications.