PROCESS FOR PREPARING HIGH DIBLOCK CONTENT MULTIBLOCK INTERPOLYMERS VIA CHAIN TRANSFER

摘要

A process of preparing a diblock/triblock composition in a single reaction vessel includes reacting a first monomer, such as styrene, with a first portion of an anionic catalyst or initiator in a suitable solvent to form a first block of the polymers. A second step includes adding a second portion of the catalyst and a second monomer, such as butadiene. A portion of the resulting living diblock polymer is then terminated by addition of a chain transfer agent, which also forms a second anionic catalyst/initiator. Further sequential additions of the second and first monomers copolymerize with both the remaining living diblock and with the second anionic catalyst to complete the triblock polymer and form a second portion of diblock polymer.