Halato‐telechelic polymers. XIV. Solution behavior of α, ω‐divalent transition metal dicarboxylato polybutadiene

A procedure is described which allows α,ω‐dicarboxylic acid polybutadiene to be end‐neutralized using a stoichiometric amount of a transition metal acetate. In a nonpolar solvent, the solution viscosity of this new class of carboxylato telechelic polymers depends on the neutralization degree of the acid end groups in such a way that the progress of the neutralization may be compared with that of a polycondensation reaction. In contrast to Cu(II), the Zn, Ni, Co, and Mn carboxylate endgroups promote very early gelation of toluene solutions when the polymer concentration increases. The particular behavior of Cu(II) can only be explained by a difference in the coordination number compared with the other elements of the first transition series. The dependence of the solution viscosity on the atomic number of the element cannot be completely accounted for so far. Nevertheless, an electrostatic association of the cupric carboxylate end groups can be disregarded, since the solution viscosity is independent of the polarity of the solvent in the range of 2.28–7.28 D.