Abstract: The supported rare earth catalytic system was synthesized and used in the gas phase polymerization of 1,3-butadiene (Bd) successfully.It is found that the catalyst of silica gel supported Nd(naph)₃-Al(i-Bu)₃-Al(i-Bu)₂Cl has a rather high catalytic activity and high sterospecificity.The catalytic system was found to have an excellent activity when n(Al)/n(Nd)=40-60, n(Cl)/n(Nd)=3-7. Adding a suitable amount of monomer, both Bd and isoprene(Ip) as seed in the preparation of catalyst can greatly increase the catalytic activity of the catalytic system, and Bd is found more effective.The polymerization rate increases rather rapidly and reaches the maximum within 10 min, then decreases slowly.The obtained p(Bd) has a molecule weight about 10⁵-10⁶with cis-1,4 structure above 98% and gel content less than 6%.

Key words: Supported rare earth catalyst, 1,3-Butadiene(Bd), Isoprene(IP) Gas phase polymerization