Molecular Structure of Polybutadienes Synthesized with a Lithium-Containing Initiation System

With the use of high-resolution NMR spectroscopy (600 MHz) and gel-permeation chromatography, the products of anionic polymerization of butadiene initiated by n-butyllithium modified with sodium and magnesium alcoholates are studied. It is shown that a change in synthesis conditions makes it possible to vary the configuration and isomeric composition and molecular parameters of polybutadienes. The distribution of 1,2-, cis-1,4-, and trans-1,4-units in a chain has a pronounced statistical character and depends on the composition of the initiation system.