CHAIN TRANSFER BY RADICAL ADDITION-FRAGMENTATION MECHANISMS - SYNTHESIS OF MACROMONOMERS AND END-FUNCTIONAL OLIGOMERS

Appropriately substituted allylic sulfides, sulfones, bromides, phosph onates, stannanes and peroxides, vinyl ethers and thionocarbonyl compo unds are effective chain transfer agents in free radical polymerizatio ns. These compounds function by a radical addition-fragmentation mecha nism by which fragments derived from the chain transfer agents are ins talled at both ends of polymer chains. This provides a convenient meth od for preparing both mono- and di-end functional oligomers and polyme rs. Allylic peroxides fragment to give epoxy end groups while the othe r allylic compounds give rise to macromonomers by introducing terminal double bonds.