Production of polyether polyols using caesium as catalyst

An alternative catalyst to the traditional KOH was studied for preparation of polyols, having high molecular weight (about 6000 g mol(-1)) and low unsaturation content. KOH catalyst is useful until the equivalent weight of the polyol reaches about 1000 g mol(-1), at which point an excess of allylic terminal unsaturation starts to develop. Polyols were synthesised using caesium and potassium hydroxide, at different temperatures and catalyst concentrations. Both the unsaturation content of the final polyol and the synthesis time decreased using caesium hydroxide instead of potassium hydroxide under the same synthesis conditions. The relationship to temperature and catalyst concentration was also studied. GPC analyses showed an additional small peak in the product, attributed to the allyl adduct, whose intensity was greater when potassium hydroxide was used as catalyst. (C) 2002 Society of Chemical Industry.