The "living" polydienes with broad molecular weight distribution(MWD) have been synthesized by means of the continuous addition of initiator (sec-Buli). The investigations on the dependence of molecular weight upon conversion

the kinetic analysis on polymerization and the block polymerization of butadiene and isoprene have been made in order to confirm the fact that the detectable termination and transfer reactions are absent in the polymerization with the continuous addition of initiator. It has been found that the MWD of polymer can be controlled and varied over a wide range when the technique of continuous addition of initiator used and polymerization conditions

(such as the initiator amount

its addition rate

monomer concentration and polymerization temperature) changed.