THE EFFECT OF THE NATURE OF ORGANOALUMINUM COMPOUND AND THE CATALYTIC-SYSTEM PREPARATION PROCEDURE ON MOLECULAR CHARACTERISTICS OF 1,4-CIS-POLYBUTADIENE

This study investigated the effect produced by the preparation procedu re of a 2-component lanthanide catalytic system and by the nature of o rganoaluminium compound on 1) the molecular characteristics of 1,4-cis -polybutadiene (PB), 2) the regularities of its average molecular weig ht (MW), and 3) molecular weight distribution (MWD). The kinetic param eters of the polymerization process were calculated. The principal reg ularities of variations in PB molecular characteristics with respect t o the polymerization conditions, i.e., OAC and monomer concentrations and temperature, are retained with different procedures of the lanthan ide catalytic system, and those present distinctive features of the ca talytic complexes studied in this article. But as for differences in M W and its patterns of dependence on monomer conversion rate and OAC na ture, these are due to changes in kinetic parameters of the polymeriza tion, which occur with the use of the catalyst prepared by a different procedure. (C) 1994 John Wiley & Sons, Inc.