ABSTRACT
Oligoethers and oligoesters of different chemical structure with terminal hydroxyl groups are the main stocks in the production of polyurethanes. A vast amount of data devoted to investigating the molecular heterogeneity of hydroxyterminated oligoethers has been accumulated in the literature. The same reaction is the reason for the appearance of functional heterogeneity. Defectiveness in FTD increases with the growing molecular weight of oligopropylene oxide. The content of cyclic propylene oxide molecules in industrial THF–PO co-polymers reaches 5%. To reduce their content it is recommended in the patent literature to wash the oligomer solution in 1,2-dichlorethane with water. As a result the cyclic tetramer content is reduced only to 1–1.5%; it proves impossible to remove it completely. The quality of oligoesters is given considerable attention owing to the fact that they lie at the basis of large-tonnage processes for the production of polyurethane foam and thermoplastics.
