An improved process for the preparation of copolymers and THF Polyetrahydrofuran

The invention relates to a method for single-step production of polytetrahydrofurane or tetrahydrofurane copolymers by polymerizing tetrahydrofurane on an acid, heterogeneous catalyst in the presence of at least one telogen and/or comonomer from the group of alpha, omega-diols, water, polytetrahydrofurane having a molecular weight of 200 - 700 Dalton and/or cyclic ether, characterized in that a) the catalyst-free polymerization discharge is divided up into at least one distillation step forming a residue containing the polymerization product and at least one tetrahydrofurane fraction, and the tetrahydrofurane fraction is at least partially recycled in the polymerization, and b) low-molecular polytetrahydrofurane and/or tetrahydrofurane copolymers having an average molecular weight of 200-700 Dalton are separated from the distillation residue of step a) and PTHF and/or THF copolymers having an average molecular weight of 650 - 5000 Dalton are obtained, and c) at least one partial amount of the separated low-molecular polytetrahydrofurane and/or tetrahydrofurane copolymer having an average molecular weight of 200 700 Dalton is recyled in the polymerization.