METHOD FOR OBTAINING OLIGOMERS OF POLYTETRAHYDROFURANE OR TETRAHYDROFURANE COPOLYMERS

摘要

The invention relates to a method for obtaining oligomers of polytetrahydrofurane or tetrahydrofurane copolymers from a raw product containing a methanolic polytetrahydrofurane or tetrahydrofurane copolymer produced during the transesterification of the monoester and/or diester of the polytetrahydrofurane or the tetrahydrofurane copolymer with the methanol. Said method is characterised in that a) the main quantity of methanol is separated from the raw product in a first distillation step, b) the bottom product obtained is separated by distillation into a head fraction containing the oligomers of the polytetrahydrofurane or the tetrahydrofurane copolymers, and polytetrahydrofurane or tetrahydrofurane copolymer, and c) the oligomers of the polytetrahydrofurane or the tetrahydrofurane copolymers are condensed out of the head fraction from step b).