Co-initiated polyether polyol and process for its preparation

摘要

Process for the preparation of a co-initiated polyether polyol, which process comprises the steps of (a) preparing a mixture of at least one aromatic initiator, at least one polyethylene glycol and optionally one or more aliphatic initiators, (b) reacting the mixture obtained in step (a) in the presence of a suitable alkoxylation catalyst with at least one alkylene oxide having three or more carbon atoms per molecule using such quantity of alkylene oxide that the polyether polyol obtained has a hydroxyl value in the range of from 150 to 400 mg KOH/g, and (c) recovering the co-initiated polyether polyol. The co-initiated polyether polyol is very suitable for (the preparation of rigid polyisocyanurate-modified polyurethane foams. Such foams have a good flame retardancy.