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Autori: Coca, S., Dimonie, M., Dragutan, V., Ion, R.M., Popescu, L., Teodorescu, M., Moise, F., Vasilescu, A
Editorial: Journal of Molecular Catalysis, 90(1-2), p.101-110, 1994.
Polymerization reactions of cyclopentene, cyclooctene and cyclododecene have been carried out in presence of catalytic systems based on tungsten tetraphenylporphyrinate, under inert atmosphere at room temperature, in aromatic solvents. The catalyst precursor was prepared by interaction of WCl6 with free tetraphenylporphyrin in CCl4 and characterized by spectroscopic methods (e.g. UV-Vis etc.). Spectroscopic studies on the interaction between the catalytic components or with the monomer, as well as kinetic results, molecular weight distribution and polymer microstructure indicated a high stability and efficiency of the catalytic systems employed. This catalyst allowed polyalkenamers with monomodal and narrow molecular weight distribution to be obtained. The polypentenamer displayed a block and/or alternate distribution of the carbon-carbon double bond dyads and high trans configuration. Data obtained under the above conditions gave information concerning the nature of active species during the initiation and propagation reactions.
Cuvinte cheie: polymerization, porphyrin, tungsten