POLYMERIZATION OF TRANSISOMERS AND CIS-IS OMERS OF 1,3-PENTADIENE ANDOTHER DIENES WITH THE HOMOGENEOUS CATALYTIC-SYSTEM VCL3-CENTER-DOT-3THF-ISO-BU3AL

Polymerization of a number of conjugated dienes with the new homogeneo us catalytic system VCl3 . 3THF-iso-Bu3Al has been studied. The polyme rs formed are characterized contain by low molecular masses and predom inantly trans-1,4-units. Unlike other coordination catalysts, the cata lytic system mentioned initiates polymerization of both 1,3-pentadiene isomers with similar rates. The kinetics of trans-pentadiene homopoly merization was studied and the number of active centers was estimated. Chain transfer to the monomer was shown to be the main termination re action. Copolymerization of four pairs of dienes was carried out and c opolymerization constants were calculated. A plausible scheme of stere oregulation in the polymerization of pentadiene isomers of both types with coordination catalysts is discussed.