MECHANISM OF GTP - CAN ALL OF THE AVAILABLE DATA BE ACCOMMODATED

Group transfer polymerization (GTP)a of acrylic monomers is a living s ystem mediated by a trialkylsilyl capped growing chain end. The fact t hat it operates at temperatures as high as 100-degrees-C differentiate s GTP from living anionic polymerization, which at best operates at 25 -degrees-C for hindered methacrylates. To accommodate all of the mecha nistic data available it appears that at least two mechanistic pathway s are required: an associative process for mild nucleophilic catalysts and a dissociative process for strong nucleophilic catalysts.