Chain transfer by radical addition‐fragmentation mechanisms: Synthesis of macromonomers and end‐functional oligomers

Appropriately substituted allylic sulfides, sulfones, bromides, phosphonates, stannanes and peroxides, vinyl ethers and thionocarbonyl compounds are effective chain transfer agents in free radical polymerizations. These compounds function by a radical addition‐fragmentation mechanism by which fragments derived from the chain transfer agents are installed at both ends of polymer chains. This provides a convenient method for preparing both mono‐ and di‐end functional oligomers and polymers. Allylic peroxides fragment to give epoxy end groups while the other allylic compounds give rise to macromonomers by introducing terminal double bonds.