RING-OPENING POLYMERIZATION OF CYCLOOLEFIN INDUCED BY TUNGSTEN PORPHYRINATES

Polymerization reactions of cyclopentene, cyclooctene and cyclododecen e have been carried out in presence of catalytic systems based on tung sten tetraphenylporphyrinate, under inert atmosphere at room temperatu re, in aromatic solvents. The catalyst precursor was prepared by inter action of WCl6 with free tetraphenylporphyrin in CCl4 and characterize d by spectroscopic methods (e.g. UV-Vis etc.). Spectroscopic studies o n the interaction between the catalytic components or with the monomer , as well as kinetic results, molecular weight distribution and polyme r microstructure indicated a high stability and efficiency of the cata lytic systems employed. This catalyst allowed polyalkenamers with mono modal and narrow molecular weight distribution to be obtained. The pol ypentenamer displayed a block and/or alternate distribution of the car bon-carbon double bond dyads and high trans configuration. Data obtain ed under the above conditions gave information concerning the nature o f active species during the initiation and propagation reactions.