Synthesis of linear polyurethanes based on α, ω-hydroxyoligobutadienes and tolylene 2,4-diisocyanate

The effects of the functionality-type distribution and molecular mass of the parent α,ω-hydroxy-oligobutadienes on the molecular parameters of linear polyurethanes synthesized by the nonequilibrium polycondensation with tolylene 2,4-diisocyanate were studied. It was shown that studying the polydispersity and molecular mass of linear polyurethanes makes it possible to draw a conclusion about competing reactions that proceed in the system, namely, allophanate formation, macrocyclization, and termination of chain propagation of a linear macromolecule in the presence of monofunctional molecules. The experimental and calculated characteristics of linear polyurethanes, which were determined taking into account the functionality-type distribution of the parent oligomer, were compared. The influence of synthetic conditions, including the ratio of the functional groups, temperature, and the presence of organometallic catalysts, on the molecular mass distribution of the resulting polyurethanes was estimated.