| 摘要 |
polymer production. SUBSTANCE: invention relates to alkanolysis of polyetherpolyol diesters, for instance tetramethylene polyether diacetate, into corresponding polyetherpolyols polyetherpolyols with two terminal hydroxyl groups, for instance into tetramethylene polyether glycol involving C1-C4-alkanol and alkali catalyst. Synthesis and separation of products are conducted in reaction distillation column, into upper part of which is fed diester along with effective amount of at least one at least oxide, hydroxide or alkoxide as catalyst, e.g. sodium methoxide, and C1-C4- alkanol, e. g. methanol. Simultaneously, alkanol vapors are fed into lower part of column. Resulting polyetherpolyol and alkanol are withdrawn from the top of column. Top distillate can be subjected to additional azeotropic separation to yield, for example, methyl acetate and unreacted methanol to be recycled. EFFECT: increased conversion of diester and improved purity of product. 8 cl, 1 dwg |
