| Abstract: | The present invention relates to a process for preparing polyether polyols by adding alkylene oxides onto H-functional starter compounds, characterized in that at least one alcohol containing at least two urethane groups is used as H-functional starter compound. The invention further provides the polyether polyols containing a structural unit of the formula (IV) where R1 is linear or branched C2 to C24-alkylene which may optionally be interrupted by heteroatoms such as O, S or N and may be substituted, preferably CH2—CH2 or CH2—CH(CH3), R2 is linear or branched C2 to C24-alkylene, C3 to C24-cycloalkylene, C4 to C24-arylene, C5 to C24-aralkylene, C2 to C24-alkenylene, C2 to C24-alkynylene, each of which may optionally by interrupted by heteroatoms such as O, S or N and/or may each be substituted by alkyl, aryl and/or hydroxyl, preferably C2 to CM alkylene, R3 is H, linear or branched C1 to C24-alkyl, C3 to C24-cycloalkyl, C4 to C24-aryl, C5 to C24-aralkyl, C2 to C24-alkenyl, C2 to C24-alkynyl, each of which may optionally be interrupted by heteroatoms such as O, S or N and/or each of which may be substituted by alkyl, aryl and/or hydroxyl, preferably H, R4, is H, linear or branched O to C24-alkyl, C24-cycloalkyl, C4 to C24-aryl, C5 to C24-aralkyl, C2 to C24-alkenyl, C2 to C24-alkynyl, each of which may be interrupted by heteroatoms such as O, S or N and/or each of which may be substituted by alkyl, aryl and/or hydroxyl, preferably H, IV is linear or branched C2 to C24-alkylene which may optionally be interrupted by heteroatoms such as O, S or N and may be substituted, preferably CH2—CH2 or CH2—CH(CH3), and where R1 to R5 may be identical or different from one another, and the polyether polyols obtainable by the process according to the invention. |
