Verfahren zur Herstellung von Polyaetherpolyolen

Polyether polyols are prepared by passing at least one 1,2-alkylene oxide having 2 to 4 carbon atoms into a mixture of sucrose and water in the presence of an oxyalkylation catalyst in an amount of at least 4 moles of alkylene oxide per mole of sucrose, allowing the reaction product to become a liquid at the reaction temperature, discontinuing addition of the alkylene oxide, removing water from the reaction mixture until the water content is less than 10% by weight of the mixture, and then continuing addition of the same or a different alkylene oxide until the desired polyether polyol is formed. The reaction is preferably carried out at a pressure of not more than 200 p.s.i. and a temperature of 70-270 DEG F. The water may be present initially in the liquid state or as water vapour or steam and may be removed at the intermediate stage by distillation, decantation or centrifuging, Preferably 10-25 equivalents of alkylene oxide are used per equivalent of sucrose. The sucrose may be partially replaced by one or more other saccharides such as lactone, glucose and a -methyl-D-glucoside. Specified alkylene oxides are ethylene, propylene, butylene and amylene oxides. Numerous catalysts are specified. In examples, using potassium hydroxide as catalyst, sucrose is reacted with (1) and (4), propylene oxide, and (5) propylene oxide followed by butylene oxide. Comparative examples are given. The polyether polyols may be reacted with isocyanates to give polyurethanes.