Polyether Polyol Initiators

Compounds containing active hydrogen atoms such as hydroxyl or amino groups are used as initiators in the production of polyether polyols. The functionality of the polyether polyol is related to the functionality of the initiator.

Polyols, polyamines, and alkanolamines can be used individually as initiators for polyether polyols, or two or three of them can be mixed together as initiators, such as toluene diamine/glycerol, sucrose/glycerol, and mannitol/ethylene glycol combinations.

Water is also a difunctional initiator and can reduce the average functionality of polyethers in the production of high-functionality polyether polyols; however, it is rarely used alone. Therefore, attention should be paid to the water content in the initiator when manufacturing polyether polyols, otherwise, the functionality of the polyether will be reduced.

Due to a small amount of disproportionation side reaction of hydroxyl groups during the base-catalyzed ring-opening polymerization of propylene oxide, the actual hydroxyl functionality of the polyether polyol is lower than the average functionality of the initiator. This difference between actual and theoretical functionality is more significant for high molecular weight polyethers.