Special Polyether Polyols – Other Specialized Polyethers

(1) Catalytically Active Polyether Polyols

Rigid foam polyether containing tertiary amine groups (such as ethylenediamine-based polyether) possesses intrinsic catalytic properties due to the presence of tertiary amines. However, polyethers containing tertiary amine groups are rare in flexible foam polyethers. Recently, to reduce amine emissions in molded polyurethane foam products for applications like automotive seat cushions, catalytically functional flexible foam polyether polyols have gained attention. Dow’s *Voranol Voractiv* polyols incorporate catalysts grafted into the polyether structure. According to Dow, catalytically active polyethers significantly reduce the need for additional amine catalysts during the foaming process, thereby lowering the release of volatile organic compounds (VOCs) in polyurethane foams. These polyols can reduce amine emissions from flexible foam products by more than 50%. Furthermore, Dow claims that *Voranol Voractiv* polyols enable consistent foam production under improved processing conditions.  

(2) Wood Flour Polyether Polyols

Reports in China suggest that wood flour, made from sawdust, shavings, and crushed wood chips, can be synthesized with polyols at atmospheric pressure and 90–125°C to produce wood flour polyether polyols. These polyols can be used to create polyurethane foam, reducing costs and endowing the foam with certain biodegradability properties.  

(3) Amino-Terminated Polyether Amines

Amino-terminated polyether amines are not polyols but polyether polyamines. They feature a poly(propylene oxide) backbone and are derived from polyether polyols, where the terminal hydroxyl groups are replaced by amine groups. The first amino-terminated polyether was developed by Texaco/Huntsman under the trade name *Jeffamine*. These polyethers are produced by reacting polyethers containing primary and secondary hydroxyl groups with hydrogen in the presence of a hydrogenation/dehydrogenation catalyst. The reaction occurs at 200–300°C and a hydrogen pressure of 20 MPa, using catalysts such as Raney nickel, Raney cobalt, diatomaceous earth-nickel, or diatomaceous earth-cobalt.  

Additionally, a patent describes synthesizing aromatic amino-terminated polyethers by reacting hydroxyl-terminated polyethers with o-chlorophenylacetic anhydride [NH2C6H4(CO)2] at 85–150°C in the presence of a strong base.  

Because amines react with isocyanates more actively than hydroxyl groups, this reduces the demolding time of products while enhancing their strength, demolding properties, high-temperature resistance, and solvent resistance. In many formulations, catalysts may not be required. Amino-terminated polyethers are primarily used in reaction injection molding (RIM) for polyurethane foams and in solvent-free sprayable polyurea elastomers.